Foreground and background segmentation related to a virtual three-dimensional (3D) video conference

ABSTRACT

A method for foreground and background segmentation related to a virtual three-dimensional (3D) video conference, the method may include segmenting each image of multiple images of a video stream, to segments, each segment has one or more properties that are constant; determining temporal properties of the segments; and classifying each segment as a background segment or a foreground segment, based at least in part, on the temporal properties of the segments.

CROSS REFERENCE

This application claims priority from U.S. provisional patent Ser. No.63/201,713 filing date May 10, 2021.

This application is a continuation in part of U.S. patent applicationSer. No. 17/249,468 filing date Mar. 2, 2021 which claims priority from(a) U.S. provisional patent application Ser. No. 63/023,836 filing dateMay 12, 2020, (b) U.S. provisional patent application Ser. No.63/081,860 filing date Sep. 22, 2020, (c) U.S. provisional patentapplication Ser. No. 63/199,014 filing date Dec. 1, 2020. All patentapplications are being incorporated herein by reference.

BACKGROUND

Video conference calls are very popular. They require that eachparticipant has their own computerized system with a camera that isusually located close to a display.

Typically, several participants in a meeting are presented in separatesmall tiles and another tile may be used for sharing one of theparticipants' screen.

Each participant is typically shown with the background of their ownoffice or with a virtual background of their selection.

Participants are displayed from different angles and in different sizes.

As a result, people may feel disconnected and not as if they were allpresent in the same room.

As the user typically looks at the screen where the faces of theopposite person are displayed and not at the camera which may be aboveor below the screen, for example, the appearing image is of a personthat is looking downwards or upwards respectively and not towards theother person. Hence, eye contact between the participants of theconversation is lost. This enhances the feeling of not being connected.

Furthermore, as on each participant's screen the other users' images maybe located at different positions and in varying order, it is not clearwho is looking at who.

Since all the audio streams from all the participants are merged intoone single mono-track audio stream, it is impossible to know from whatdirection the sound arrives, and this may make it difficult to determinewho is talking at any given moment.

As most webcams grab an image of the face from the middle of the chestand upwards, the participants' hands are frequently not shown andtherefore hand gestures that are a significant part of normalconversations are not conveyed in a typical video conference.

Furthermore—the quality of traffic (bit rate, packet loss and latency)may change over time and the quality of the video conference calls mayfluctuate accordingly.

Typically, video conferencing images tend to be blurry due to thelimited resolution of the camera (1080×720 pixels in common laptopcameras), motion blur, and video compression. In many cases the videofreezes and audio sounds metallic or is lost.

All these limitations cause an effect that is widely known as Zoomfatigue (https://hbr.org/2020/04/how-to-combat-zoom-fatigue) whichresults in participants becoming more tired after many hours of videoconferencing meetings than they typically do in normal meetings in thesame room.

There is a growing need to enhance the virtual interaction betweenparticipants and to overcome various other problems associated withcurrent video conference call services.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a method;

FIG. 2 illustrates an example of a computerized environment;

FIG. 3 illustrates an example of a computerized environment;

FIG. 4 illustrates an example of data structures;

FIG. 5 illustrates an example of a process for amending a direction ofview of a 3D model of a part of a participant according to a directionof gaze of the participant;

FIG. 6 includes examples of methods;

FIG. 7 is an example of images and a process;

FIG. 8 is an example of parallax correction;

FIG. 9 illustrates an example of a 2.5-dimension illusion;

FIG. 10 illustrates an example of 3D content for a 3D screen or virtualreality headset;

FIG. 11 is an example of a panoramic view of a virtual 3D environmentpopulated by five participants, a partial view of the some of theparticipants within the virtual 3D environment, and a hybrid view;

FIG. 12 is an example of images of different exposure and an example ofimages of faces of different shades;

FIG. 13 is an example of an image of a face and a segmentation of theimage;

FIG. 14 illustrates an example of a method;

FIG. 15 is an example of a 3D model and a UV map;

FIG. 16 is an example of 2D-to-2D dense correspondences computation onupper and lower lips;

FIG. 17 is an example of a method;

FIG. 18 is an example of methods;

FIG. 19 is an example of methods;

FIG. 20 illustrates a texture map of a face;

FIG. 21 illustrates examples of methods;

FIG. 22 illustrates examples of an image that captures two persons, andexamples of avatars that represents one or more persons or even moreparticipants;

FIG. 23 illustrates examples of directions of gaze of a participant;

FIG. 24 illustrates an example of a method;

FIG. 25 illustrates an example of a computerized environment, a sharedfolder and various signals exchanged between user devices;

FIG. 26 illustrates examples of timing diagrams;

FIG. 27 illustrates examples of methods;

FIG. 28 illustrates an example of an image and foreground and backgroundsegmentation;

FIGS. 29, 31 and 32 illustrates examples of methods;

FIG. 30 illustrates an example of an avatar;

FIG. 33 illustrates different parts of a virtual 3D video conference;

FIG. 34 illustrates an example of a participant having lipstick on itslips; and

FIGS. 35, 36 and 37 illustrate an avatar of the participant of FIG. 34without lipstick, the lips of the avatar without lipstick and the avatarwith lipstick.

DESCRIPTION OF THE DRAWINGS

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the embodiments ofthe disclosure.

However, it will be understood by those skilled in the art that thepresent embodiments of the disclosure may be practiced without thesespecific details. In other instances, well-known methods, procedures,and components have not been described in detail so as not to obscurethe present embodiments of the disclosure.

The subject matter regarded as the embodiments of the disclosure isparticularly pointed out and distinctly claimed in the concludingportion of the specification. The embodiments of the disclosure,however, both as to organization and method of operation, together withobjects, features, and advantages thereof, may best be understood byreference to the following detailed description when read with theaccompanying drawings.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

Because the illustrated embodiments of the disclosure may for the mostpart, be implemented using electronic components and circuits known tothose skilled in the art, details will not be explained in any greaterextent than that considered necessary as illustrated above, for theunderstanding and appreciation of the underlying concepts of the presentembodiments of the disclosure and in order not to obfuscate or distractfrom the teachings of the present embodiments of the disclosure.

Any reference in the specification to a method should be applied mutatismutandis to a system capable of executing the method and should beapplied mutatis mutandis to a computer readable medium that isnon-transitory and stores instructions for executing the method.

Any reference in the specification to a system should be applied mutatismutandis to a method that may be executed by the system and should beapplied mutatis mutandis to a computer readable medium that isnon-transitory and stores instructions executable by the system.

Any reference in the specification to a computer readable medium that isnon-transitory should be applied mutatis mutandis to a method that maybe applied when executing instructions stored in the computer readablemedium and should be applied mutatis mutandis to a system configured toexecute the instructions stored in the computer readable medium.

The term “and/or” means additionally or alternatively.

Any reference to a “user” should be applied mutatis mutandis to the term“participant”—and vice versa.

There is provided a method, a non-transitory computer readable mediumand a system related to video and may, for example be applicable to 3Dvideo conference calls. At least some of the examples and/or embodimentsillustrated in the applications may be applied mutatis mutandis forother purposes and/or during other applications.

For example, referring to a 3D video conference that involves multipleparticipants. A first participant is imaged, and a second participantwishes to view a first avatar (or any other 3D visual representation) ofthe first participant within a virtual 3D video conference environment.

The generation of the first avatar (or any other 3D visualrepresentation) may be executed in various manners—for example—only by adevice of the second participant, only by the device of the firstparticipant, partially by the device of the second participant,partially by the device of the first participant, by a cooperationbetween the devices of the first and second participants, by anothercomputerized system (such as but not limited to a cloud system or aremote system), and/or any combination of one or more devices.

The inclusion of the avatar (or any other 3D visual representation)within the virtual 3D video conference environment may be executed invarious manners—for example—only by a device of the second participant,only by the device of the first participant, partially by the device ofthe second participant, partially by the device of the firstparticipant, by a cooperation between the devices of the first andsecond participants, by another device (such as but not limited to acloud device or a remote device), and/or any combination of one or moredevices.

Any reference to one manner of execution of any step of the generationof the first avatar and/or any reference to one manner of execution ofany step of the inclusion of the avatar within the virtual 3D videoconference environment may be applied mutatis mutandis to any othermanner of execution.

The generation of the first avatar and/or the inclusion of the firstavatar may be responsive to information gained by the device of thefirst user or to a camera or sensor associated with the device of thefirst user. A non-limiting example of information may includeinformation regarding the first participant and/or information regardingto the acquisition of images of the first participant (for examplecamera setting, illumination and/or ambient conditions).

The system may include multiple user devices and/or intermediate devicessuch as servers, cloud computers, and the like.

FIG. 1 illustrates an example of method 200.

Method 200 is for conducting a three-dimensional video conferencebetween multiple participants.

Method 200 may include steps 210, 220 and 230.

Step 210 may include receiving direction of gaze information regarding adirection of gaze of each participant within a representation of avirtual 3D video conference environment that is associated with theparticipant.

The representation of a virtual 3D video conference environment that isassociated with the participant is a representation that is shown to theparticipant. Different participants may be associated with differentrepresentation of a virtual 3D video conference environment.

The direction of gaze information may represent a detected direction ofgaze of the participant.

The direction of gaze information may represent an estimated directionof gaze of the participant.

Step 220 may include determining, for each participant, updated 3Dparticipant representation information within the virtual 3D videoconference environment, that reflects the direction of gaze of theparticipant. Step 220 may include estimating how the virtual 3D videoconference environment will be seen from the direction of gaze of theparticipant.

Step 230 may include generating, for at least one participant, anupdated representation of virtual 3D video conference environment, theupdated representation of virtual 3D video conference environmentrepresents the updated 3D participant representation information for atleast some of the multiple participants. Step 230 may include renderingimages of the virtual 3D video conference environment for at least someof the multiple participants. Alternatively—step 230 may includegenerating input information (such as 3D model and/or one or moretexture maps) to be fed to a rendering process.

Method 200 may also include step 240 of displaying, by a device of aparticipant of the multiple participants, an updated representation ofthe virtual 3D video conference environment, the updated representationmay be associated with the participant.

Method 200 may include step 250 of transmitting the updatedrepresentation of virtual 3D video conference environment to at leastone device of at least one participant.

The multiple participants may be associated with multiple participantdevices, wherein the receiving and determining may be executed by atleast some of the multiple participant devices. Any step of method 200may be executed by at least some of the multiple participant device orby another computerized system.

The multiple participants may be associated with multiple participantdevices, wherein the receiving and determining may be executed by acomputerized system that differs from any of the multiple participantdevices.

Method 200 may include one of more additional steps—collectively denoted290.

The one or more additional steps may include at least one out of:

-   -   a. Determining a field of view of a third participant within the        virtual 3D video conference environment.    -   b. Setting a third updated representation of the virtual 3D        video conference environment that may be sent to a third        participant device to reflect the field of view of the third        participant.    -   c. Receiving initial 3D participant representation information        for generating the 3D representation of the participant under        different circumstances. The different circumstances may include        at least one out of (a) different image acquisition conditions        (different illumination and/or collection conditions), (b)        different directions of gaze, (c) different expressions, and the        like.    -   d. Receiving in run time, circumstances metadata; and amending,        in real time, the updated 3D participant representation        information based on the circumstances metadata.    -   e. Repetitively selecting for each participant, a selected 3D        model out of multiple 3D models of the participant.    -   f. Repetitively smoothing a transition from one selected 3D        model of the participant to another 3D model of the participant.    -   g. Selecting an output of at least one neural network of the        multiple neural networks based on a required resolution.    -   h. Receiving or generating participants appearance information        about head poses and expressions of the participants.    -   i. Determining the updated 3D participant representation        information to reflect the participant appearance information.    -   j. Determine a shape of each of the avatars that represent the        participants.    -   k. Determining relevancy of segments of updated 3D participant        representation information.    -   l. Selecting which segments to transmit, based on the relevancy        and available resources.    -   m. Generating a 3D model and one or more texture maps of 3D        participant representation information of a participant.    -   n. Estimating 3D participant representation information of one        or more hidden areas of a face of a participant.    -   o. Estimating 3D model hidden areas and one or more hidden parts        texture maps.    -   p. Determining a size of the avatar.    -   q. Receiving audio information regarding audio from the        participants and appearance information.    -   r. Synchronizing between the audio and the 3D participant        representation information.    -   s. Estimating face expressions of the participants based on        audio from the participants.    -   t. Estimating movements of the participants.

The receiving of the 3D participant representation information may bedone during an initialization step.

The initial 3D participant representation information may include aninitial 3D model and one or more initial texture maps.

The 3D participant representation information may include a 3D model andone or more texture maps.

The 3D model may have separate parameters for shape, pose andexpression.

Each of the one or more texture maps may be selected and/or augmentedbased on at least one out of shape, pose and expression.

Each of the one or more texture maps may be selected and/or augmentedbased on at least one out of shape, pose, expression and angularrelationship between a face of the participant and an optical axis of acamera that captures an image of face of the participant.

The determining, for each participant, of the updated 3D participantrepresentation information may include at least one of the following:

-   -   a. Using one or more neural network for determining the updated        3D participant representation information.    -   b. Using multiple neural networks for determining the updated 3D        participant representation information, wherein different neural        networks of the multiple neural networks may be associated with        different circumstances.    -   c. Using multiple neural networks for determining the updated 3D        participant representation information, wherein different neural        networks of the multiple neural networks may be associated with        different resolutions.

The updated representation of the virtual 3D video conferenceenvironment may include an avatar per participant of the at least someof the multiple participants.

A direction of gaze of an avatar within the virtual 3D video conferenceenvironment may represent a spatial relationship between a (a) directionof gaze of a participant that may be represented by the avatar and (b) arepresentation of the virtual 3D video conference environment displayedto the participant.

The direction of gaze of an avatar within the virtual 3D videoconference environment may be agnostic to an optical axis of a camerathat captured a head of the participant.

An avatar of a participant within the updated representation of thevirtual 3D video conference environment may appear in the updatedrepresentation of the virtual 3D video conference environment as beingcaptured by a virtual camera located on a virtual plane that crosses theeyes of the first participant. Accordingly—the virtual camera and theeye may be located, for example at the same height.

The updated 3D participant representation information may be compressed.

The updated representation of the virtual 3D video conferenceenvironment may be compressed.

The generating of the 3D model and one or more texture maps may be basedon images of the participant that were acquired under differentcircumstances.

The different circumstances may include different viewing directions ofa camera that acquired the images, different poses, and differentexpressions of the participant.

The estimating of the 3D participant representation information of oneor more hidden areas may be executed by using one or more generativeadversarial networks.

The determining, for each participant, of the updated 3D participantrepresentation information may include at least one out of:

-   -   a. Applying a super-resolution technique.    -   b. Applying noise removal.    -   c. Changing an illumination condition.    -   d. Adding or changing wearable item information.    -   e. adding or changing make up information.

The updated 3D participant representation information may be encrypted.

The updated representation of virtual 3D video conference environmentmay be encrypted.

The appearance information may be about head poses and expressions ofthe participants and/or be about lip movements of the participants.

The estimating face expressions of the participants based on audio fromthe participants may be executed by a neural network trained to mapaudio parameters to face expression parameters.

FIG. 2 illustrates an example of a computational environment thatinclude users devices 4000(1)-4000(R) of users 4010(1)-4010(R). Index rranges between 1 and R, R being a positive integer. The r'th user device4000(r) may be any computerized device that may include one or moreprocessing circuit 4001(r), a memory 4002(r), a man machine interfacesuch as a display 4003(r), and one or more sensors such as camera4004(r). The r'th user 4010(r) is associated with (uses) the r'th userdevice 4000(r). The camera may belong to the man machine interface.

The users devices 4000(1)-4000(R) and a remote computerized system 4100may communicate over one or more networks such as network 4050. The oneor more networks may be any type of networks—the Internet, a wirednetwork, a wireless network, a local area network, a global network, andthe like.

The remote computerized system may include one or more processingcircuits 4101(1), a memory 4101(2), and may include any other component.

Any one of the users devices 4000(1)-4000(R) and a remote computerizedsystem 4100 may participate in the execution of any method illustratedin the specification. Participate means executing at least one step ofany of said methods.

Any processing circuit may be used—one or more network processors,non-neural network processors, rendering engines, image processors andthe like.

One or more neural networks may be located at a user device, at multipleusers devices, at a computerized system outside any of the user devices,and the like.

FIG. 3 illustrates an example of a computational environment thatinclude users devices 4000(1)-4000(R) of users 4010(1)-4010(R). Index rranges between 1 and R, R being a positive integer. The r'th user device4000(r) may be any computerized device that may include one or moreprocessing circuit 4001(r), a memory 4002(r), a man machine interfacesuch as a display 4003(r), and one or more sensors such as camera4004(r). The r'th user 4010(r) is associated with (uses) the r'th userdevice 4000(r).

The users devices 4000(1)-4000(R) may communicate over one or morenetworks such as network 4050.

Any one of the users devices 4000(1)-4000(R) may participate in theexecution of any method illustrated in the specification. Participatemeans executing at least one step of any of said methods.

FIG. 4 illustrates an example of various data structures. The datastructures may include user avatars 4101(1)-4101(j), texture maps4102(1)-4102(k), 3D models 4103(1)-4103(m), 3D representations ofobjects 4104(1)-4104(n), and any mapping or other data structuresmentioned in the application.

Any user may be associated with one or more data structure of anytype—avatar, 3D model, texture map, and the like.

Some of the examples refer to a virtual 3D video conference environmentsuch as a meeting room, restaurant, cafe, concert, party, external orimaginary environment in which the users are set. Each participant maychoose or be otherwise associated with a virtual or actual backgroundand/or may select or otherwise receive any virtual or actual backgroundin which avatars related to at least some of the participants aredisplayed. The virtual 3D video conference environment may include oneor more avatars that represents one or more of the participants. The oneor more avatars may be virtually located within the virtual 3D videoconference environment. One or more features of the virtual 3D videoconference environment (that may or may not be related to the avatars)may differ from one participant to another.

Either the full body, the upper part of the body or just the face of theusers are seen in this environment—thus an avatar may include full bodyof a participant, the upper part of a body of the participant body orjust the face of the participant.

Within the virtual 3D video conference environment there may be providedan improved visual interaction between users that may emulate the visualinteraction that exists between actual users that are actuallypositioned near each other. This may include creating or ceasing to haveeye-contact, expressions directed at specific users and the like.

In a video conference call between different users, each user may beprovided with a view of one or more other users—and the system maydetermine (based on gaze direction and the virtual environment)—wherethe user looks (for example at one of the other users—at none of theusers, at a screen showing a presentation, at a whiteboard, etc.)—andthis is reflected by the virtual representation (3D model) of the userwithin the virtual environment—so that other users may determine wherethe user is looking.

FIG. 5 illustrates an example of a process for amending a direction ofview of an avatar of a part of a participant according to a direction ofgaze of the participant. The upper part of FIG. 5 is a virtual 3D videoconference environment—represented by a panoramic view 41 of fiveparticipants 51, 52, 53, 54 and 55 sitting near table 60. Allparticipants face the same direction—the screen.

In the lower image the avatar of the fifth participant faces the avatarof first participant—as the fifth participant was detected to look atthe 3D model of the first participant within the environment aspresented to the fifth participant.

Tracking the user's eyes and gaze direction may also be used todetermine the direction in which the user is looking (direction of gaze)and at which person or object the user is looking. This information canbe used to rotate the avatar's head and eyes so that in the virtualspace it also appears as if the user is looking at the same person orobject as in the real world.

Tracking the user's head pose and eye gaze may also be used to controlthe virtual world's appearance on the user's screen. For example, if theuser looks at the right side of the screen, the point of view of thevirtual camera may move to the right, so that the person or object atwhich the user is looking is located at the center of the user's screen.

The rendering of a user's head, body, and hands from a certain point ofview that is different than the original point of view of the camera maybe done in different ways, as described below:

In one embodiment, a 3D model and texture maps are created before thebeginning of the meeting and this model is then animated and rendered atrun time according to the user's pose and expressions that are estimatedfrom the video images.

A texture map is a 2D image in which each color pixel represents thered, green and blue reflectance coefficients of a certain area in the 3Dmodel. An example of a texture map is shown in FIG. 20 . Each colorpixel in the texture map corresponds to certain coordinates within aspecific polygon (e.g., triangle) on the surface of the 3D model.

An example of a 3D model composed of triangles and the mapping of thetexture map to these triangles is shown in FIG. 15 .

Generally, each pixel in the texture map has an index of the triangle towhich it is mapped and 3 coordinates defining its exact location withinthe triangle.

A 3D model composed of a fixed number of triangles and vertices may bedeformed as the 3D model changes. For example, a 3D model of a face maybe deformed as the face changes its expression. Nevertheless, the pixelsin the texture map correspond to the same locations in the sametriangles, even though the 3D locations of the triangles change as theexpression of the face changes.

Texture maps may be constant or may vary as a function of time,expression or of viewing angle. In any case, the correspondence of agiven pixel in a texture map and a certain coordinate in a certaintriangle in the 3D model doesn't change.

In yet another embodiment, a new view is created based on a real-timeimage obtained from a video camera and the position of the new point ofview (virtual camera).

In order to best match between the audio and the lip movement and facialexpressions, the audio and video that is created from the rendering ofthe 3D models based on the pose and expressions parameters aresynchronized. The synchronization may be done by packaging the 3D modelparameters and the audio in one packet corresponding to the same timeframe or by adding time stamps to each of the data sources.

To further improve the natural appearance of the rendered model, aneural network may be trained to estimate the facial expressioncoefficients based on the audio. This can be done by training the neuralnetwork using a database of videos of people talking and thecorresponding audio of this speech. The videos may be of the participantthat should be represented by an avatar or of other people. Given enoughexamples, the network learns the correspondence between the audio (i.e.phonemes) and the corresponding face movements, especially the lipmovements. Such a trained network would enable to continuously renderthe facial expressions and specifically the lip movements even when thevideo quality is low or when part of the face is obstructed to theoriginal video camera.

In yet another embodiment, a neural network can be trained to estimatethe audio sound from the lip and throat movements or from any otherfacial cues, as is done by professional lip readers. This would enableto create or improve the quality of the audio when the audio is brokenor when there are background noises that reduce its quality.

In yet another embodiment a neural network is trained to compress audioby finding a latent vector of parameters from which the audio can bereconstructed at a high quality. Such a network could serve to compressaudio at a lower bit rate than possible with standard audio compressionmethods for a given audio quality or obtain a higher audio quality for agiven bit rate.

Such a network may be trained to compress the audio signal to a fixednumber of coefficients, subject to the speech being as similar aspossible to the original speech under a certain cost function.

The transformation of the speech to a set of parameters may be anonlinear function and not just a linear transformation as is common instandard speech compression algorithms. One example would be that thenetwork would need to learn and define a set of basis vectors which forma spanning set of spoken audio.

The parameters then would be the vectorial coefficients of the audio asspanned by this set.

FIG. 6 illustrates method 2001.

Method 2001 is for conducting a 3D video conference between multipleparticipants, the method may include steps 2011 and 2021.

Step 2011 may include determining, for each participant, updated 3Dparticipant representation information within the virtual 3D videoconference environment, that represents participant. The determining maybe based on audio generated by the participants and appearanceinformation about appearance of the participants.

Step 2021 may include generating, for at least one participant, anupdated representation of virtual 3D video conference environment, theupdated representation of virtual 3D video conference environmentrepresents the updated 3D participant representation information for atleast some of the multiple participants. For example, any movement bythe participant may expose or collude parts of the environment.Additionally, movements by participant may affect lighting in the roomas the movements may modify the exposure to light of different parts ofthe environment.

The method may include matching between the audio from a certainparticipant and appearance information of a certain participant.

The appearance information may be about head poses and expressions ofthe participants.

The appearance information may be about lip movements of theparticipants.

Creation of 3D Models

The 3D models and texture maps of the users can be created on the flyfrom a 2D or 3D video camera or can be prepared before the beginning ofthe 3D video conference call. They can also be a combination of ahigh-quality model prepared before the meeting and a real-time modelcreated during the meeting. For example, changes in the appearance ofthe participant relative to the high-quality model, such as a newlygrown beard, may be adjusted using information from the on-the-flycamera. As another example, a new texture map can be created from thevideo during the meeting based on the current look of the person.However, this texture map may include dead zones (hidden areas) due toobstructions of areas that may be not currently seen by the camera. Suchdead zones can be filled by using a previously created texture map.

Filling these zones is performed by matching landmarks in the twotexture maps using a method known as registration. Once matching isperformed, data for the hidden areas is taken from the previouslyprepared texture map.

Illumination corrections between the current and previous texture mapscan be calculated based on the areas that may be shown in both maps.These corrections may be applied to the current texture map, so thatthere may be no distinct border line between the textures captured atdifferent times. In addition, in order to avoid sharp transitionsbetween textures from different times, a continuous blending of thetextures can be applied, e.g., by using a weighted average of the twotexture maps, where the weights change along a transition zone betweenthe textures. The methods mentioned above may be used for mergingtexture maps, material maps and also 3D models.

If the video camera is a 2D camera, then computerized models, such asconvolutional neural networks may be used to create a 3D model from the2D images. These models may be parametric models where the parametersdetermine the shape, expression and pose of the face, body, and hands.Such a model can be trained by using sets of 2D images and corresponding3D models. The corresponding 3D models can be created in several ways.In the rendering process different illuminations can be used in order tomake the model robust to varying illuminations.

In another method, many 2D images of real people can be obtained andthen a 3D model can be created from these multiple 2D images by usingphotogrammetric software. In yet another method a depth camera that alsoincludes an RGB camera, such as the Kinnect camera or the IntelRealSense camera can be used to obtain both 3D depth models andcorresponding 2D images. After training the network using the methodsdescribed above, at run time it may be supplied with a 2D image as aninput and the network outputs the 3D model. The 3D model can be outputas a point cloud, a mesh or a set of parameters that describe a 3D modelin a given parametric space.

If the camera is a 3D depth camera, then the depth data can be used tomake the models more accurate and solve ambiguities. For example, if oneobtains only a front facing image of a person's head, it may beimpossible to know the exact depth of each point in the image, i.e. thelength of the nose. When more than one image of the face from differentangles exist, then such ambiguities may be solved. Nevertheless, theremay remain occluded areas seen in only one image or inaccuracies. Thedepth data from a depth camera may assist in generating a 3D model withdepth information in every point that solves the ambiguity problemsdescribed above.

If an offline 3D model creation process may be used, then this can bedone using a single image, multiple images, a video, or several videos.The user may be asked to rotate the head, hands, and body so that it maybe seen from many angles in order to cover all views and avoid missingareas in the model.

If such areas still exist, then they may be extrapolated or guessed fromthe modelled areas or by a neural network that was trained using manyexamples.

Specifically, a Generative Adversarial Network (GAN) may be trainedbased on many images of a certain person or on many images of multiplepeople to generate images of people from angles that may be differentthan the angle at which the camera may be currently seeing the person.

At runtime, such a network would receive an image of a person as aninput and a camera position from which the person should be rendered.The network would render an image of that person from the differentcamera position including parts that may be obscured in the input imageor may be at a low resolution in the input image due to being almostparallel to the camera's line of sight (i.e. cheeks at a frontal image).

FIG. 7 shows an example of a process 100 that uses a GenerativeAdversarial Network 109 complete textures in areas that may be not seenin the original image. With GANs there may be no need to build acomplete and accurate 3D model with a full texture map and then renderit.

An image 101 is input into a neural network 103 that outputscharacteristics 105 of the image (that may include texture parameters,expression parameters and/or shape parameters)—for example the neuralnetwork may expands texture parameters into a texture map. The neuralnetwork may also receive additional information 102 and generatecharacteristics 105 also based on the additional information.

A differentiable renderer 107 may renders an image 108 from the texturemap, expression and shape parameters. This image may have missing partsdue to occlusions of parts of the head that were not seen in theoriginal input image. A Generative Adversarial Network 109 (GAN) maycomplete the rendered image into a full image 110 without any missingparts.

A generative Adversarial Network (GAN) may also be used in order tocorrect illumination in the texture map of the model, for example incases where the user's face may be not illuminated uniformly, e.g. thereexists a strong illumination from a window at the side of the face orfrom a spot projector above the user's head.

GAN networks may also be used to correct the 3D model, e.g. create earsthat may be not properly seen in the images, for example, due toobstruction by the cheeks or by hair.

The user may also be requested to pose or do different facialexpressions so that a comprehensive model of poses and expressions canbe created. Examples of such poses and expressions may be smiling,frowning, opening and closing the mouth and eyes.

The 3D model may have separate parameters for shape, pose andexpression. The shape parameters may depend only on the specific personand may be independent of the pose and expression. Therefore, theyremain constant even when a person moves his head and talks or makesvarious facial expressions. Therefore, during the modelling process of acertain person, the expression and pose of the person being modelled donot have to be static or frozen during the capturing of the video orimages that may be used to create the 3D model. Since the shape of the3D model is considered to be static, there is no need to use a 3D cameraor a set of 2D cameras which would otherwise be needed to create a 3Dmodel. This relieves the requirement to use several multi-view camerasthat may be temporally synchronized. All the models created frommultiple images may be merged into one 3D model or into severaldifferent models that vary with the expression or illuminationconditions, but all have common shape parameters.

During the real time rendering process, the closest model or models interms of viewing angle or illumination may be chosen as a starting pointfor the model transformation and rendering process.

For example, if different models that refer to viewing angles of 0, 10,20, 30 and 40 degrees are available, and at a given moment the userwants to view a model at a 32 degrees angle, then the modelcorresponding to 30 degrees viewing angle may be chosen as a startingpoint for the model transformation.

Furthermore, several such models may be interpolated or extrapolated toobtain a model at a state that may be not part of the pre-recordedstates.

During the process of creating the 3D avatar, the 3D model and the 2Dtexture maps, the quality of the 3D model that may be created may beevaluated by projecting it onto two dimensional images from differentangles using a simple linear geometrical projection or a more complexmodel of a camera that includes optical distortions. The projections ofthe 3D model to 2D images may be compared to the images grabbed by thecamera or cameras. In doing so, it may be useful to model the camerathat may be used to grab the images so that the geometrical distortionsof the camera may be modelled in the projection process. The modellingmay include, but may be not limited to modelling the focal length of thecamera, the pixel size, the total Field of View, nonlinear geometricaldistortions such as a barrel or pincushion distortion or any otherdistortions of optics and especially for cameras with a wide field ofview such as a fisheye camera.

The modelling may also include modelling blurring due to the optics andcolor distortions. The projections of the 3D model can be compared tothe grabbed 2D images in order to verify that the 3D geometricalstructure may be accurate and also that the reflection maps may beaccurate.

Several methods may be used to compare the projections and the grabbedimages such as:

-   -   a. Comparing the location of facial landmarks such as the        corners of the eyes and lips, the tip and edges of the nose and        the edges of the cheeks and chin, that may be found in the image        pairs.    -   b. Comparing the location of silhouettes.    -   c. Comparing the location of corners and lines detected in both        images.    -   d. Comparing the grey levels of the two images.

Any differences that may be found may be used to update the 3D model andthe reflectance maps in a manner that reduces the differences betweenthe projected images and the grabbed images. For example, if it may befound that the corner of an eye may be positioned too far to the left inthe projection of the 3D model compared to its location in a grabbed 2Dimage, then the model can be revised so that the location of the cornerof the eye will move to the right in order to reduce the error betweenthe location of that landmark in the projection and grabbed images.

This can be done by changing the location of 3D points in a 3D mesh orby changing the parameters in a parametric model that affect thelocation of that landmark.

This process may be used to reduce the errors in the rendered andgrabbed images and thus improve the quality of the models that may becreated.

Specifically, it may be useful to project images at different anglessuch as 0, 45 and 90 degrees in order to capture any geometrical or greylevel differences between the model and the grabbed images.

The quality of the 3D model and the texture maps may be analysed duringor after the process of the creation of the avatar and specificallyinspected to verify that all or some of the following cases may becovered:

-   -   a. There may be no obscured areas in the facial, body or hands        models.    -   b. All relevant expressions may be covered.    -   c. Both open and closed eyes may be modelled.    -   d. Both closed and open mouths with teeth showing may be        covered.    -   e. There may be no areas with low resolution due to imaging of a        facial structure that may be nearly parallel to the line of        sight, e.g. imaging the cheeks from a front view.    -   f. The illumination may be appropriate and there may be no areas        that may be too dark or too bright and saturated.    -   g. There may be no areas that may be too noisy.

The model may be not significantly different from the current appearanceof the user in the video images, e.g. due to shaving or adding a beardor changing hairstyles.

In case the inspection process discovers that there may be missinginformation, the user may be requested to add additional photos or videosequences in order to complete the missing information.

Before the beginning of a call between users, but after the user'scamera has started to grab images of the user, the 3D model and texturemaps may be enhanced to reflect the new appearance of the user as seenat that moment.

Information from a previously created model and texture map may bemerged with updated information obtained before the start of the meetingor during the meeting. For example new information regarding theillumination of the person's body and face, the user's hair, shaving,makeup, clothes, etc. may be used to update the 3D model and texturemaps. Areas that were not seen before such as the top of the head orbottom of the chin or other parts of the body that may be seen before orduring the session may also be used to update the 3D model or texturemaps.

The new information may be used to replace previous information, may beaveraged with previous information, or otherwise merged with previousinformation.

In order to scale the 3D model, i.e., know its exact dimensions from a2D camera where the camera parameters may be unknown and the range tothe modelled object may be unknown, several methods may be used. Forexample:

-   -   a. Using an object of known size that may be placed next to the        object, e.g., place a credit card on the forehead of the user.        Such objects can include but may be not limited to credit cards,        driver's license, bills, coins, rulers, etc. In such cases a        classification method may classify the object used and determine        its size from a database. For example, a method may detect a        bill as originating from one of multiple countries and/or        denominations, recognize it and obtain its size from a database.        Similarly, a method may detect a ruler and determine its size        from the readings on the ruler.    -   b. Asking the user to specify his/her height. The height of the        face may be known to be approximately 13% of the height of an        adult. This may be an accurate enough approximation for the        requirements of many applications. In addition, it may be known        that children and babies have different body proportions. For        babies, the height of the face may be known to be approximately        25% of its height. The size of the face may be a nonlinear        function of the height, e.g., 25% of the height for people who        may be 60 cm high, 20% of the height for people that may be 100        cm high and 13% of the height for people that may be 150 cm or        higher.

The 3D model of the user may include, but may be not limited to:

-   -   a. A parametric model of the face and body i.e. shape,        expression and pose.    -   b. A high frequency depth map detailing such fine details as        wrinkles, skin moles, etc.    -   c. A reflectance map detailing the color of each part of the        face or body. Multiple reflectance maps may be used to model the        change of appearance from different angles.    -   d. An optional material map detailing the material from which        each polygon may be made, e.g. skin, hair, cloth, plastic,        metal, etc.    -   e. An optional semantic map listing what part of the body each        part in the 3D model or reflectance map represents.    -   f. These models and maps may be created before the meeting,        during the meeting or may be a combination or models created        before and during the meeting.

The user's model may be stored on the user's computer, phone or otherdevice. It may also be transmitted to the cloud or to other users,possibly in an encrypted manner in order to preserve the user's privacy.

FIG. 6 may also illustrate method 90 for generating and using aparametric model.

Method 90 may include steps 92, 94, 96 and 98.

Step 92 may include generating, by a user device, a 3D model related toa user, the 3D model may be a parametric model.

Step 94 may include sending the parameters of the 3D model to acomputerized system.

Step 96 may include monitoring each participant by a user device of theparticipant, during the conference call, updating parameters of 3D modelof each participant accordingly and sending updated parameters (sendingmay be subjected to communication parameters).

Step 98 may include receiving by a user device of each participantupdated parameters of 3D models related to other participants andupdating the display accordingly to reflect the changes to the model.

FIG. 6 also illustrates method 1800 for generating a 3D visualrepresentation of a sensed object that may be three dimensional.

Method 1800 may include steps 1810, 1820 and 1830.

Step 1810 may include obtaining at least one 3D visual representationparameter, the visual representation parameters may be selected out of asize parameter, a resolution parameter, and a resource consumptionparameter.

Step 1820 may include obtaining object information that represents thesensed object; and selecting, based on the at least one parameter, aneural network for generating the visual representation of the sensedobject. For example, the information that represents the sensed objectmay be the viewing angle of the object.

Steps 1810 and 1820 may be followed by step 1830 of generating the 3Dvisual representation of the 3D object by the selected neural network.

Step 1830 may include at least one out of:

-   -   a. Generating a 3D model of the 3D object and at least one 2D        texture map of the 3D object.    -   b. Further processing the 3D model and the 2D texture map during        a rendering process of at least one rendered image.

The generating may be executed by a first computerized unit, wherein thegenerating may be followed by sending the 3D model and the at least one2D texture map to a second computerized unit configured to render atleast one rendered image based on the 3D model and the at least one 2Dtexture map.

The 3D object may be a participant of a 3D video conference.

The method may include outputting the 3D visual representation from theselected set of neural network outputs.

The 3D object may be a participant of a 3D video conference.

Super Resolution and Performing Touch-Ups on a 3D Model.

In order to enhance the resolution of the 3D model, super resolutiontechniques may be used. The super-resolution technique is used toenhance the resolution of the 3D model or the deformable texture map ofthe 3D model. For example, several images of the model with sometranslation or rotation between them may be used in order to create agrid at a higher resolution than the grid that can be created from asingle image. Note that the color values of the model may be related topolygons in a 3D mesh or to pixels in a 2D texture map.

This process may be done using a recursive process. At the first stage a3D model and a texture map that are an up-sampled interpolation of thelow-resolution model and texture map are used as an initial guess. These3D model and texture map have more vertices and pixels than in theoriginal 3D model and texture map but do not include more details. Theup-sampled model and texture map are then used to render an image of thetextured model from a viewpoint that is similar to that of the camera.

The rendered image is compared to the 2D image that was taken with thecamera.

The comparison may be performed by, but not limited to, subtraction ofthe two images or by subtraction after global alignment of the image orby subtraction after a local alignment of areas in the images. Theresult of the comparison, which is a difference image obtained by thisprocess, includes details from the original camera image that do notexist in the rendered image. The differences may be used as a feedbackto enhance the resolution of the initial 3D model and texture map.

The enhancement may be done by, but not limited to, adding thedifference image to the initial guess in order to get a new guess withmore details. The new 3D model and texture map may be again rendered toobtain a second rendered image that is compared to the original cameraimage to create a second difference image that may be used as feedbackfor enhancing the resolution of the 3D model and texture map.

This process may be repeated a given number of times or until a certaincriterion is met, e.g., the difference between the actual camera imageand the rendered image is below a certain threshold. The process isrepeated where the comparison of the rendered textured 3D model isperformed with several camera images from a set of images, such as froma video sequence. Since there may be many images in the image set orvideo, at each image the 3D model and texture map may be sampled by thecamera at different positions.

Hence, the process can create a 3D model and texture map that is basedon an effectively higher sampling rate than is available from a singleimage. As a result of this process, a 3D model with more vertices and atexture map with more pixels are created and these 3D model and texturemap exhibit high resolution details that are not apparent in theoriginal low resolution 3D model and texture map.

Multiple images of the face and body may also be acquired from the sameor different angles in order to average these images and by this meansto improve the signal to noise ratio, i.e., create a model with a lowerlevel of pixel noise. This may be especially useful if the images may beacquired at low illumination conditions and the resulting images may benoisy.

Super resolution techniques based on learning methods may also beapplied. In such schemes a machine learning method such as aConvolutional Neural Network may be trained based on pairs of highresolution and low-resolution images or 3D models, so that thecorrespondence between low- and high-resolution images or models may belearned. During the rendering process, the method receives alow-resolution image or model as input and outputs a correspondinghigh-resolution image or model. These types of methods may be especiallyuseful for generating sharp edges at the transition between differentfacial organs, such as sharp edges along the eyes or the eyebrows.

Note that the transformation from low to high resolution may beperformed based on a single image or multiple images and that it may beperformed in the process of creating a 3D model, a texture map or whenrendering the final image that may be presented to the user.

Reducing the random noise in the 3D model and the 2D texture maps mayalso be performed using denoising methods. Such methods may includelinear filtering techniques, but preferably nonlinear, edge-preservingtechniques, such as a bilateral filter, anisotropic diffusion orconvolutional neural networks, that reduce random noise while preservingedges and fine details in the image of the 3D model.

The user's appearance may be altered and improved by manipulating theresulting 3D model or the reflectance maps. For example, different kindsof touch-ups may be applied such as removing skin wrinkles, applyingmakeup, stretching the face, lip filling or changing the eyes' color.

The shape of the user's body may also be altered, and the user's clothesmay be changed from the real clothes to other clothes according to theuser's wish. Accessories such as earrings, glasses, hats, etc. may alsobe added to the user's model.

Alternatively objects such as glasses or headphones may be removed fromthe user's model.

Communications System Based on the 3D Models.

During the communication session, i.e., a 3D video conference callbetween several users, a 2D or 3D camera (or several cameras) grabsvideos of the users. From these videos a 3D model (for example—the bestfitting 3D model) of the user may be created at a high frequency, e.g.,at a frame rate of 15 to 120 fps.

Temporal filters or temporal constraints in the neural network may beused to assure a smooth transition between the parameters of the modelcorresponding to the video frames in order to create a smooth temporalreconstruction and avoid jerkiness of the result.

The real-time parametric model together with the reflectance map andother maps may be used to render a visual representation of the face andbody that may be very close to the original image of the face and bodyin the video.

Since this may be a parametric model, it may be represented by a smallnumber of parameters. Typically, less than 300 parameters may be used tocreate a high-quality model of the face including each person's shape,expression and pose.

These parameters may be further compressed using quantization andentropy coding such as a Huffman or arithmetic coder.

The parameters may be ordered according to their importance and thenumber of parameters that may be transmitted and the number of bits perparameter may vary according to the available bandwidth.

In addition, instead of coding the parameters' values, the differencesof these values between consecutive video frames may be coded.

The model's parameters may be transmitted to all other user devicesdirectly or to a central server. This may save a lot of bandwidth asinstead of sending the entire model of the actual high-quality imageduring the entire conference call—much fewer bits representing theparameters may be transmitted. This may also guarantee a high quality ofthe video conference call, even when the current available bandwidth maybe low.

Transmitting the model parameters directly to the other users instead ofvia a central server may reduce the latency by about 50%.

The other user devices may reconstruct the appearance of the other usersfrom the 3D model parameters and the corresponding reflectance maps.Since the reflectance maps, representing such things as a person's skincolor change very slowly, they may be transmitted only once at thebeginning of the session or at a low updating frequency according tochanges that occur in these reflectance maps.

In addition, the reflectance maps and other maps may be updated onlypartially, e.g., according to the areas that have changed or accordingto semantic maps representing body parts. For example, the face may beupdated but the hair or body that may be less important forreconstructing emotions may not be updated or may be updated at a lowerfrequency.

In some cases, the bandwidth available for transmission may be limited.Under such conditions, it may be useful to order the parameters totransmit according to some prioritization and then transmit theparameters in this order as the available bandwidth allows. Thisordering may be done according to their contribution to the visualperception of a realistic video. For example, parameters related to theeyes and lips may have higher perceptual importance than those relatedto cheeks or hair. This approach would allow for a graceful degradationof the reconstructed video.

The model parameters, video pixels that may be not modelled and audiomay be all synchronized.

As a result, the total bandwidth consumed by the transmission of the 3Dmodel parameters may be several hundred bits per second and much lowerthan the 100 kbps-3 Mbps that may be typically used for videocompression.

A parametric model of the user's speech may also be used to compress theuser's speech beyond what may be possible with a generic speechcompression method. This would further reduce the required bandwidthrequired for video and audio conferencing. For example, a neural networkmay be used to compress the speech into a limited set of parameters fromwhich the speech can be reconstructed. The neural network is trained sothat the resulting decompressed speech is closest to the original speechunder a specific cost function. The neural network may be a nonlinearfunction, unlike linear transformations used in common speechcompression algorithms.

The transmission of bits for reconstructing the video and audio at thereceiving end may be prioritized so that the most important bits may betransmitted or receive a higher quality of service. This may include butmay not be limited to prioritizing audio over video, prioritizing of themodel parameters over texture maps, prioritizing certain areas of thebody or face over others, such as prioritizing information relevant tothe lips and eyes of the user.

An optimization method may determine the allocation of bitrate orquality of service to audio, 3D model parameters, texture maps or pixelsor coefficients that may be not part of the model in order to ensure anoverall optimal experience. For example, as the bitrate is reduced, theoptimization algorithm may decide to reduce the resolution or updatefrequency of the 3D model and ensure a minimal quality of the audiosignal.

Encryption and Security of a 3D Model

A user's 3D model and corresponding texture maps may be saved on auser's device, a server on the cloud or on other users' devices. Thesemodels and texture maps may be encrypted in order to secure the personaldata of the user. Before a call between several users, a user's devicemay request access to other users' 3D models and texture maps so thatthe device will be able to render the models of the other users based ontheir 3D geometry.

This process may include exchange of encryption keys at a highfrequency, e.g., once every second, so that after the call ends, userswill not be able to access other users' 3D models and texture maps orany other personal data.

A user will be able to determine which other users may have access tohis/her 3D model and texture maps or any other personal data.

Furthermore, a user may be able to delete personal data that may besaved on the user's device, a remote computer, or other users' devices.

The 3D model and texture maps of a user that may be stored on the user'sdevice or on a central computer may be used to authenticate that theperson in front of the 2D or 3D camera may indeed be the user, and thismay save the need to log in to the system or service with a password.

Another security measure may involve protecting access and usage (forexample a display of the avatar during the 3D video conference) one ormore avatars of one or more participant—this can be done by applying aDigital Rights Management method which enables the access and usage ofavatar (or avatars)—or by using any other authentication-based accesscontrol to the access and/or usage of the avatar. The authentication mayoccur multiple times during a 3D video conference. The authenticationmay be based on biometrics, may require a password, may include faceidentification methods based on either 2D images, 2D videos (withmotion) or based on 3D features.

Parallax Correction, Eye-Contact Creation and 3D Effects Based on a 3DModel.

The mentioned below correction may correct any deviations between theactual optical axis of the camera and a desired optical axis of avirtual camera. While some of the example refer to the height of thevirtual camera, any of the following may also refer to the laterallocation of the camera—for example positioning the virtual camera at thecenter of the display (both height and lateral location, positioning thevirtual camera to have a virtual optical axis that is directed to theeyes of a participant (for example via a virtual optical axis that maybe perpendicular to the display or have any other spatial relationshipwith the display).

Assuming that a certain user is imaged by a camera of the user—the otheruser devices may reconstruct the 3D model of that user from differentangles than the angle that in which the original video (of the user) wasgrabbed by the camera.

For example, in many video conferencing situations, the video camera maybe placed above or below the user's eye level. When a first user looksat the eyes of a second user as they are presented on the first user'sscreen, the first user does not look directly into the camera.Therefore, the image as captured by the camera and as presented to otherusers, would show the first user's eyes as gazing downwards or upwards(depending on the location and optical axis of the camera).

By rendering the 3D model from a point directly ahead of the user'sgaze, the resulting image of the user may seem to look directly at theeyes of the other user.

FIG. 8 illustrates an example of a parallax correction. Image 21′ may bethe image acquired by a camera 162 while the camera 162 is located ontop of display 161 and has an actual optical axis 163 (directed towardsa downright direction) and actual field of view 163 that may be directedtowards fifth participant 55.

The corrected image 22′ may be virtually acquired by a virtual camera162′ having a virtual optical axis 163′ and a virtual field of view 163′the virtual camera may be located at the point of the screen at theheight of the eyes and directly in front of the fifth participant 155.

A face location tracker may track the location of viewer's face andchange the rendering point of view accordingly. For example, if theviewer moves to the right, he/she may see more of the left side of theopposite person and if he/she moves to the left, he/she may see more ofthe right side of the opposite person.

This may create a 3D sensation of viewing a 3-dimensional person orobject, even while using a 2D screen.

FIG. 9 illustrates an example of a 3D illusion created by a 2D device.The image acquired by the camera (and the tracker's FOV) may be denoted35 and various virtual images may be denoted 31, 32 and 33.

This may be obtained by modifying the rendered image according tomovements of the viewer and the viewer's eyes, thus creating a 3Deffect. In order to do this, an image of the viewer is acquired by acamera such as a webcam.

A face detection algorithm detects and tracks the face within the image.Additionally, the eyes of the viewer are detected and tracked within theface. As the face of the viewer moves, the algorithm detects thelocation of the eyes and calculates their position in a 3D world. A 3Denvironment is rendered from a virtual camera according to the locationof the viewer's eyes.

If the rendered image is presented on a 2D screen, then only one imageis rendered. This image of the 3D environment may be rendered from thepoint of view of a camera that is positioned in between the eyes of theviewer.

If the viewer uses a 3D display such as a 3D display or a virtualreality (VR) headset or glasses, then two images corresponding to theviewpoint of the right and left eyes may be generated to create astereoscopic image.

FIG. 10 illustrates an example of two stereoscopic images (denoted 38and 39) presented on a 3D screen or VR headset.

Some 3D displays such as auto-stereoscopic displays do not requireglasses to present a 3D image. In such 3D displays the different imagesmay be projected at different angles, e.g., using lenticular arrays, sothat each eye views a different image. Some auto-stereoscopic displays,such as the Alioscopy Glasses-Free 3D Displays project more than 2images at different angles, and up to 8 different images in the case ofsome Alioscopy displays. If using such a display, more than two imagesmay be rendered to create the 3D effect on the screen. This brings asignificant improvement over traditional 2D video conferencing systemsin creating a more realistic and intimate sensation.

To enhance the 3D sensation, 3D audio can also be used. For each user,his/her location in the virtual 3D setting relative to all other usersmay be known. A stereophonic signal of each user's speech can be createdfrom a monophonic audio signal by creating a delay between the audiosignals for the right and left ears according to the relative positionof the audio source. In such a manner, each user gets a sensation of thedirection from which the sound originated and therefore who may betalking.

Furthermore, the images of the face of the users and specifically theirlips may be used to perform lip reading.

Analysis of consecutive images of lips can detect movement of the lips.Such movement can be analyzed, for example, by a neural network that istrained to detect when lip movement is associated with talking. As inputfor the training phase, it is possible to have a sound analyzer or ahuman being tag input video sequences as having human sound. If theperson is not talking, then the system may automatically mute that userand thus reduce background noise that may be coming from the environmentof the user.

The lip reading may also be used to know which sounds may be expected tobe produced by the user. This may be used to filter external noise thatdoes not correlate with those expected sounds, i.e. not in the expectedfrequency range, and use this to filter background noise when the usermay be talking.

Lip reading may also be used to assist in the transcription ofconversations that may be carried on the system in addition to speechrecognition methods that may be based only on audio.

This can be performed, for example by a neural network. The network istrained using video sequences of people speaking and associated textthat was spoken during the sequences. The neural networks can beRecurrent Neural Networks, with or without LSTM or any other type ofneural network. A method that may be based both on the audio and thevideo may result in improved speech recognition performance.

A face, body, and hands may be modelled using a limited number ofparameters as explained above.

However, in real world video conferencing not all the pixels in theimage correspond to the model of the face, body and hands. Objects thatmay be not part of the body may appear in the image.

As an example, a person speaking in a conference may be holding anobject that is significant to the specific conference call or may not besignificant at all. The speaker may be holding a pen which has nosignificance to the meeting or a diagram which is very significant tothe meeting. To transmit these objects to the other viewers, they may berecognized and modelled as 3D objects. The model may be transmitted tothe other users for reconstruction.

Some parts of the video image may not be modelled as 3D objects and maybe transmitted to the other users as pixel values, DCT coefficients,wavelet coefficients, wavelet zero-trees or any other efficient methodfor transmitting these values. Examples include flat objects placed inthe background such as a white board or a picture on a wall.

The video image and the model of the user may be compared, for example,but not limited to subtracting the rendered image of the model and thevideo image. This is done by rendering the model as if it was taken fromthe exact location of the actual camera. With perfect model andrendering the rendered image and the video image should be identical.The difference image may be segmented to areas in which the modelaccurately enough estimates the video image and areas in which the modelmay be not accurate enough or does not exist. All the areas that may benot modelled accurately enough may be transmitted separately asdescribed above.

Under some circumstance, the system may decide that some objects viewedwould not be modelled as mentioned above. In these cases the system maydecide to transmit to viewers a video stream that would include at leastsome of the non-modelled parts and then the 3D models that exist wouldbe rendered on top of the transmitted video in their respectivelocations.

The users may be provided with one or more views of the virtual 3D videoconference environment—whereas the user may or may not select the fieldof view—for example, a field of view that includes all of the otherusers or only one or some of the users, and/or may select or may viewone or some objects of the virtual 3D video conference environment suchas TV screens, whiteboards, etc.

When combining the video pixels and the rendered 3D models, the areascorresponding to the model, the areas corresponding to the video pixelsor both may be processed so that the combination may appear natural anda seam between the different areas would not be apparent. This mayinclude but may be not limited to relighting, blurring, sharpening,denoising or adding noise to one or some of the image components so thatthe whole image appears to originate from one source.

Each user may use a curved screen or a combination of physical screensto that the user in effect can see a panoramic image showing a 180 or360 degree view (or any other angular range view) of the virtual 3Dvideo conference environment and/or a narrow field of view imagefocusing on part of the virtual 3D video conference environment such asa few people, one person, only part of a person, i.e. the person's face,a screen or a whiteboard or any one or more parts of the virtual 3Dvideo conference environment.

The user will be able to control the part or parts of the narrow fieldof view image or images by using a mouse, a keyboard, a touch pad or ajoystick or any other device that allows to pan and zoom in or out of animage.

The user may be able to focus on a certain area in the virtual 3D videoconference environment (for example a panoramic image of the virtual 3Dvideo conference environment) by clicking on the appropriate part in thepanoramic image.

FIG. 11 illustrates an example of a panoramic view 41 of the virtual 3Dvideo conference environment populated by five participants and apartial view 42 of the some of the participants within the virtual 3Dvideo conference environment. FIG. 11 also illustrates a hybrid view 43that includes a panoramic view (or a partial view) and expanded imagesof faces of some of the participants.

The user may be able to pan or zoom using head, eyes, hands, or bodygestures. For example, by looking at the right or left part of thescreen, the focus area may move to the left or right, so it appears atthe center of the screen, and by leaning forward or backwards the focusarea may zoom in or out.

The 3D model of the person's body may also assist in correctlysegmenting the body and the background. In addition to the model of thebody, the segmentation method will learn what objects may be connectedto the body, e.g., a person may be holding a phone, pen or paper infront of the camera. These objects will be segmented together with theperson and added to the image in the virtual environment, either byusing a model of that object or by transmitting the image of the objectbased on a pixel level representation. This may be in contrast toexisting virtual background methods that may be employed in existingvideo conferencing solutions that may not show objects held by users asthese objects are not segmented together with the person but rather aspart of the background that has to be replaced by the virtualbackground.

Segmentation methods typically use some metric that needs to be exceededin order for pixels to be considered as belonging to the same segment.However, the segmentation method may also use other approaches, such asFuzzy Logic, where the segmentation method only outputs a probabilitythat pixels belong to the same segment. If the method detects an area ofpixels with a probability that makes it unclear if it and it is not surewhether the area should be segmented as part of the foreground orbackground, the user may be asked how to segment this area.

As part of the segmentation process, objects such as earphones, cablesconnected to the earphones, microphones, 3D glasses or VR headsets maybe detected by a method. These objects may be removed in the modellingand rendering processes so that the image viewed by viewers does notinclude these objects. The option to show or eliminate such objects maybe selected by users or may be determined in any other manner—forexample based on selection previously made by the user, by other users,and the like.

If the method detects more than one person in the image, it may ask theuser whether to include that person or people in the foreground and inthe virtual 3D video conference environment or whether to segment themout of the image and outside of the virtual 3D video conferenceenvironment.

In addition to using the shape or geometrical features of objects inorder to decide whether they may be part of the foreground orbackground, the method may also be assisted by knowledge about thetemporal changes of the brightness and color of these objects. Objectsthat do not move or change have a higher probability of being part ofthe background, e.g., part of the room in which the user may be sitting,while areas where motion or temporal changes may be detected may beconsidered to have a higher probability of belonging to the foreground.For example, a standing lamp would not be seen as moving at all and itwould be considered part of the background. A dog walking around theroom would be in motion and considered part of the foreground, In somecases periodic repetitive changes or motion may be detected, for examplewhere a fan rotates, and these areas may be considered to have a higherprobability of belonging to the background.

The system will learn the preferences of the user and use the feedbackregarding which objects, textures or pixels may be part of theforeground and which may be part of the background and use thisknowledge in order to improve the segmentation process in the future. Alearning method such as a Convolutional Neural Network or other machinelearning method may learn what objects may be typically chosen by usersas parts of the foreground and what objects may be typically chosen byusers as part of the background and use this knowledge to improve thesegmentation method.

Automatic Exposure Control for Digital Still and Video Cameras

The segmentation of the user's face and body from the background mayassist in setting the user's camera's exposure time so that the exposuremay be optimal for the face and body of the user and may be not affectedby bright or dark areas in the background.

Specifically, the exposure may be set according to the brightness of theuser's face, so that the face may be neither too dark nor too bright andsaturated.

In determining the correct exposure for a face that may be detected,there may be a challenge of knowing the actual brightness of theperson's skin. It may be preferable not to over-expose the skin ofpeople with naturally dark skins (see image 111 of FIG. 12 ) and turnthem into fair-skinned faces in the over-exposed image—see image 112 ofFIG. 12 .

In order not to over-expose images of people with dark skin, theauto-exposure method may set the exposure according to the brightnesslevel of the white of the eyes or the teeth of the user. The exposure ofthe camera may vary slowly and not change abruptly form frame to frameusing some temporal filtering. Such a method would ensure that theresulting video may be not jittery. Furthermore, such a method may allowto set the exposure based on the brightness level of the eyes or teetheven when the eyes or teeth appear in some frames and are not appear inseveral other frames.

The detection of the face, eyes or teeth may be based on the 3D modeland texture maps, on a method that detects these parts of the body or ona tracking method. Such methods may include algorithms such as the ViolaJones algorithm or neural networks that were trained to detect faces andspecific facial parts. Alternatively, a fitting of the 2D image to a 3Dmodel of the face may be performed, where the location of all the facialparts in the 3D model is known beforehand.

In another embodiment, the correct darkness of the skin can be estimatedin a Hue, Saturation and Brightness color coordinate system. In such acoordinate system, the Hue and Saturation do not change as a function ofthe exposure and only the Brightness coordinate changes. It has beenfound that a correspondence can be found between the Hue and Saturationvalues of people in adequate exposures and the respective Brightnessvalues of their skin. For example, pinkish skin tints correspond tofair-skinned faces and brownish tints correspond to dark skins—see forexample images 121-126 of FIG. 12 .

In yet another embodiment, a neural network such as a ConvolutionalNeural Network or any other network can be trained to identify thecorrespondence between the shape of the face and other attributes of theface and the skin brightness. Then at run time, images of a face atvarious exposures can be analysed independently of the chosen exposureand the detected attributes can be used to estimate the correctbrightness of the skin which may be then used to determine the exposureof the camera that results in such a skin brightness.

A neural network may be trained to find this relation-function orcorrelation between the Hue and Saturation of the skin and therespective Brightness in properly exposed images. At the inferencestage, the neural network would suggest the appropriate exposure for apicture based on the Hue and Saturation of the skin in an image that isnot necessarily at the optimal exposure, e.g., is too bright or toodark. This calculated exposure may be used to grab an appropriatelyexposed image that is neither too dark nor too bright.

In yet another embodiment, users of a photographic device such as amobile phone, professional camera, or webcam may be asked once to take aphoto of themselves or other people with a white paper or othercalibration object for reference. This calibration process may be usedto determine the correct hue, saturation and brightness values of theskin of those people. Then at run time, a computation device can run amethod that recognizes the given person and adjusts the exposure andwhite balance so that the person's skin corresponds to the correct skincolor as found in the initial calibration process.

Performing Calculations on the Cloud

The processing of this system may be performed on the user's device suchas a computer, a phone or a tablet or on a remote computer such as aserver on the cloud. The computations may also be divided and/or sharedbetween the user's device and a remote computer, or they may beperformed on the user's device for users with appropriate hardware andon the cloud (or in any other computation environment) for other users.

The estimation of the body and head parameters may be done based oncompressed or uncompressed images. Specifically, they can be performedon compressed video on a remote computer such as a central computer onthe cloud or another user's device. This would allow normal videoconferencing systems to send compressed video to the cloud or anotheruser's computer where all the modelling, rendering and processing wouldbe performed.

Using Multiple Screens and Channels to Present Information in a videoConferencing Application and Methods for Increasing the Efficiency ofMeetings

The virtual meeting may appear to take place in any virtual environmentsuch as a room, any other closed environment, or in any openenvironment. Such an environment may include one or more screens,whiteboards or flipcharts for presenting information. Such screens mayappear and disappear, may be moved, enlarged and reduced in sizeaccording to the users' desire.

Multiple participants may share their screen (or any other content) tomore than one screen. This means that multiple sources of informationmay be viewed simultaneously.

Materials for sharing or presentation may be pre-loaded to such screensor to a repository before the meeting begins for easy access during themeeting.

One possible method of presenting the different materials is bytransmitting them over dedicated streams—one for each presentedmaterial. In this setting, streams may be assigned to viewers based onmany criteria. For example, a stream may be assigned specifically to oneor more viewers. Alternatively, streams may be assigned according totopics or other considerations. In such cases, the viewed stream may beselected by each viewer. This can be quickly done by using the keyboard,the mouse or any other device. Such selection may be much faster thanthe common practice of sharing one's content which currently may requirerequesting permission to share a screen from the meeting's manager,receiving such permission, clicking a “screen share” button andselecting the relevant window to share.

Such “screen sharing” processes may take (for example) up to a minute.In various applications “screen sharing” may be repeated many times bymany different participants that present their material and a lot ofvaluable time may be lost. The suggested solution may reduce theduration to several seconds.

In some instances, not all the participants in a meeting or the screensor other interesting objects in the 3D virtual environment may appearconcurrently on the viewer's screen. This might happen, for example, ifthe field of view of the screen is smaller than a field of view neededto view all the participants. In such a case it may be necessary to movethe field of view of a viewing user to the right, left, forwards,backwards, up or down in order to change the point of view and seedifferent participants or objects. This can be achieved by differentmeans, such as but not limited to:

-   -   a. Using the keyboard arrows or other keys to pan and tilt the        viewpoint or to zoom in and out.    -   b. Using the mouse or other keys to pan and tilt the viewpoint        or to zoom in and out.    -   c. Using a method that tracks the user's head position or eye        gaze direction or a combination of both to pan and tilt the        viewpoint or to zoom in and out. The input to the method can be        a video of the user from a webcam or any other 2D or 3D camera        or any other sensor such as an eye-gaze sensor.    -   d. Using a method that tracks the user's hands to pan and tilt        the viewpoint or to zoom in and out. The input to the method can        be a video of the user from a webcam or any other 2D or 3D        camera or any other sensor such as an eye-gaze sensor.    -   e. Determining who may be the speaker at any moment and pan,        tilt and zoom in on that speaker at any given moment. If several        people may be speaking at the same time, then the method can        determine who may be the dominant speaker and pan and tilt to        that speaker or may zoom out to a wide field of view in which        several speakers may be shown.

The calculations required for creating the avatars in the virtual 3Dvideo conference environment may be performed on a user's computingdevice, in the cloud or in any combination of the two. Specifically,performing the calculations on the user's computing device may bepreferable to ensure faster response time and less delay due tocommunications with a remote server.

Two or more 2D or 3D cameras may be placed in different positions aroundthe user's screen, e.g., integrated at the borders or corners of theuser's screen, so that there may be simultaneous views of the user fromdifferent directions in real time. The 2D or 3D views from differentdirections can be used to create a 3D textured model that corresponds tothe user's appearance in real time.

If the cameras are 3D cameras, then the 3D depth obtained by the camerascan be merged into a 3D model which would be more complete than a modelobtained from only one camera, as the two or more cameras captureadditional areas to what can be captured with only one camera.

Since the cameras are located at different places, they obtain slightlydifferent information about the user and each camera may be able tocapture areas that are hidden and unseen by other cameras. If thecameras are 2D cameras, then different methods may be used to estimate a3D model of the user's face. For example, photogrammetric methods may beused to achieve this task. Alternatively, a neural network may be usedto estimate a 3D model which would produce the images as captured by thecameras.

The color images, as captured by the cameras, may be used to create acomplex texture map. This map would then cover more areas than can becaptured by only one camera. Multiple texture maps as obtained from eachcamera, may be stitched together while averaging the overlapping areas,to create one more comprehensive texture map. This may also be performedby a neural network.

This real-time 3D textured model can then be used to render the view ofthe user from various angles and camera positions and specifically maybe used to correct the viewing position of the virtual camera as if itwere virtually located inside the screen of the user—for example—at avirtual location positioned at location that a height and/or laterallocation coordinate of at the participant's eyes.

The virtual location may be positioned within an imaginary plane thatvirtually crosses the eyes of the participant—the imaginary plane may(for example) be normal or substantially normal to the display. In thisway, a sensation of eye contact may be created for the real time videoof the users. The real-time 3D textured model may also be relighteddifferently than the lighting of the real person in the realenvironment, to create a more pleasant illumination, e.g., anillumination with less shadowing.

A speech recognition or Text to Speech method or neural network may beapplied to the audio streams to summarize the contents of theconversation taking place in a virtual meeting. For example, a neuralnetwork may be trained on full body texts and their respectivesummaries. Similarly, a neural network can be trained to produce a listof action items and assignees.

In order to facilitate the process, and assist the neural network inreaching decisions, a human may signify the relevant parts of the textfor the summary of the task list. This may be done in real time, inproximity to when the relevant text is spoken. The summary and list ofaction items may be distributed to all the meeting's attendees or to anyother list of recipients. This can be used to enhance the meeting andincrease its productivity.

A digital assistant may also assist in controlling the application,e.g., to assist in inviting recipients, presenting information toscreens or to control other settings of the application.

A digital assistant may be used to transcribe the meeting in real timeand present the transcription on users' screens. This may be very usefulwhen the audio received at the remote participants' side may bedeteriorated due to echoes or to an accent that may be hard tounderstand or to problems with the communications network such as lowbandwidth or packet loss.

A digital assistant may be used to translate the speech from onelanguage to another language in real time and present the translation onusers' screens. This may be very useful when the participants speakdifferent languages. Furthermore, a Text To Speech (TTS) engine may beused to create an audio representation of the translated speech. Aneural network, such as a Generative Adversarial Network or RecursiveNeural Network can be used to create a naturally sounding speech and nota robotic speech. Such a network may also be trained and then used tocreate a translated speech that has the same intonation as in theoriginal speech in the original language.

Another neural network such as a Convolutional Neural Network may beused to animate 3D models' faces and lips to move according to thegenerated translated speech. Alternatively, a GAN or other network maybe used to generate 2D image sequences of faces and lips movingaccording to the generated translated speech. For this, a neural networkcan be trained to learn lip movement and face distortions as they relateto speech. Combining all the processes described above, an imagesequence and corresponding audio of a person speaking in one languagemay be transformed into an image sequence and corresponding audio of aperson speaking in another language, where the audio sounds natural andthe image sequence corresponds to the new audio, i.e. the lip movementsmay be in synchronization with the phonemes of the speech.

Such a system as described above may be used but may be not limited tovideo conferencing applications, television interviews, automaticdubbing of movies or e-learning applications.

Method for Precise 3D Tracking of Faces Via Monocular RGB Video

To track the user's facial pose and expressions a method for precise 3Dtracking of faces via monocular RGB video input (without depth) may bebeneficial. The method needs to detect 3D movements of faces in a videoin relation to the camera as well as various expressions, e.g., smiles,frowns and neck pose changes.

Typically monocular video based face tracking may be done using a sparseset of landmarks (as in dlib based landmarks, HR-net facial landmarksand Google's media pipe landmarks).

These landmarks may be typically created using a sparse set of userannotated images, or synthetically using parametric 3D models.

The limitations of these traditional methods are:

-   -   a. Lack of landmarks in certain areas (ears, neck).    -   b. Sparseness of landmarks.    -   c. Precision and stability of the landmarks.    -   d. Temporal coherence.    -   e. Mapping the landmarks to a 3D model.

The input to the suggested method may be a 2D monocular video, atemplated 3D model of a face (general) with deformation model (perperson or general) for this 3D template (specified below) together withan approximation (specific parameters) of the tracked parameters of thefirst frame of the video: approximated deformation parameters (of theperson) in the video and an approximated camera model.

A 3D face template mesh (templated 3D model)—may include a coarsetriangular mesh of a generic human face. By coarse, we mean in the orderof 5K or 10K polygons, which may be sufficient to represent the generalshape but not wrinkles, microstructures or other fine details.

A 3D face deformation model for the template may include a standardparametric way to deform the template and change the general shape ofthe 3D mesh (jaw structure, nose length, etc), the expression of theface (smile, frown, etc) or the rigid position and orientation of it,based on positions and cues found in the images. The user of the methodcan choose to use a statistical 3DMM as a deformation model, such as theBasel Face Model/Facewarehouse/Flame models and/or use deformationpriors such as As-Rigid-As-Possible, elasticity or isometry objectives.

Approximated deformation parameters of the person in the video and anapproximated camera model can be found by standard 3DMM fittingtechniques, for example by using a face landmark detection method todetect known face parts parameters and optimize the camera andpre-annotated landmarks in a least-squared sense. The initializationdoes not need to be precise but only approximated and can be generatedvia commonly known techniques.

The output of our method may be the geometry (deformation parameters andmesh models) per-frame, and a set of approximated camera parameters foreach image.

At each frame, the deformed mesh will be referred to as the current 3Dface mesh, and its deformation parameters on top of the template may bechosen based on a set of landmarks deduced from the 2D face partssegmentation and the pre-annotated segmentation. To that end, thesuggested method may use a 2D face parts segmentation method, inconjunction with a classical 2D rigid registration technique utilizingan ICP (Iterative Closest Point) method to track and deform a model of a3D face based on an input RGB monocular video.

The suggested method builds upon common face parts segmentationnetworks, that annotate each pixel with a given face part.

FIG. 13 illustrates face segmentation. Input image 131 may be a colorimage acquired by a camera. Image 132 illustrates a segmentation ofdifferent face parts, visualized by different colors.

In addition, the triangular mesh template may be pre-annotated with apredefined annotation of face parts (e.g. nose, eyes, ears, neck, etc).The mesh annotation may assist in finding correspondences betweenvarious face parts on the 3D model to face parts on a given targetimage. The face parts annotation may be done only once on the 3Dtemplate, such that the same annotation can be used for multiple peopleautomatically. The annotation can be specified by listing the trianglebelonging to each face part, or by using UV coordinates for the meshalong with a 2D texture map for colouring face parts in different colorsas in FIG. 12 .

FIG. 14 illustrates method 1700.

The method may perform the following process for each pair ofconsecutive video frames (noted as first image and secondimage)—including one or more iterations of steps 171-175.

Step 171 may include computing the current 2D positions of various faceparts landmarks in first image given the current 3D face mesh and cameraparameters.

Step 171 may include using the previous iteration's model of thedeformed face mesh and the camera screen space projection parameters,the method uses the camera's extrinsic and intrinsic parameters toperform a perspective projection on the 3D face mesh to get the 2Dscreen space pixel locations of each visible annotated face part vertex.Using the 3D pre-annotation (FIG. 15 —see 3D model 141 and UV map 142)the method finds the 2D position of vertices in each face part bymatching the annotations.

Step 172 may include computing the 2D location of various face partslandmarks in second image.

Step 172 may include performing a face parts segmentation method toannotate each pixel of the image—if the pixel doesn't belong to thebackground the method saves the specified face part it belongs to (eyes,nose, ears, lips, eyebrows, etc) as an annotation.

Step 173 may include computing 2D→2D dense correspondences between thefirst image face parts' 2D locations and the second image face parts 2Dlocations.

Step 173 may include finding, for each face part, correspondencesbetween the first image face part points and the second image ones byrunning a symmetric ICP method(https://en.wikipedia.org/wiki/Iterative_closest_point). The ICP methoditeratively goes between two steps: in the first step one findscorrespondences between a first image shape and a second image shape,greedily by choosing for each point in the first image shape, theclosest point on the second image shape. In the second step oneoptimizes and finds a rotation and translation that optimally transformsthe first image points to the second image points in the least-squaressense. To find an optimal solution, the process repeats these two stepsuntil convergence which occurs when a convergence metric is satisfied.

Here the first image shape may be the current 2D positions of variousface parts and the second image may be the 2D locations given by thesegmentation map (see explanation above). The ICP rigid fit may be doneseparately for each face part. For example, for each visible projectednose pixel in first image we find a corresponding pixel on the secondimage nose, given by the face parts segmentation on the target image.

Step 174 may include computing 3D→2D dense correspondences between firstimage 3D locations and second image 2D locations.

Step 175 may include deforming the face mesh to match thecorrespondences.

Step 174 may include using a rasterizer and the given camera parametersto back-project 2D pixels rendered from the 3D face mesh and first imagecamera model back to their 3D location on the mesh, specified bybarycentric coordinates. Thus, the method creates correspondencesbetween face part points in 3D on the mesh, to a second image locationin 2D under the camera's perspective projection.

Step 175 may include using a deformation model (e.g., a 3DMM asexplained above) to deform the face mesh and change the cameraparameters such that the projection of the first image 3D featuresmatches the 2D locations of the second image 2D locations, as in atypical sparse landmarks and camera fitting.

Steps 171-175 may be repeated until a convergence metric is satisfied.

For example—as in a correspondence and fitting procedures, the abovesteps may be repeated until convergence: at each step we find differentand better correspondences and optimize for them. Convergence isachieved when a convergence metric is satisfied.

This method creates a set of landmarks in areas and face parts that maynot be covered by traditional landmark methods, like ears, necks andforehead and this is due to the use of the 3D mesh. The method creates adense set of landmarks and the dense correspondences require almost noannotation except for a one-time annotation of the face parts in the 3Dmodel template. The method creates a dense set of high-qualitylandmarks, that may be temporarily coherent due to the regression whichis performed. Coherence in this context means that the landmarks do notjitter between frames.

It also allows to get landmarks on various faces or body parts e.g.,ears and neck, by simply employing common segmentation/classificationmethods.

FIG. 16 may be an illustration of the 2D-to-2D dense correspondencescomputation on the upper lips (pixels colored the same in both imagescorrespond to each other).

FIG. 17 illustrates a method that include a sequence of steps, 71, 72,73 and 74.

Step 71 may include obtaining a virtual 3D environment. This may includegenerating or receiving instructions that once executed will cause thevirtual 3D environment to be displayed to users. The virtual 3Denvironment can be a virtual 3D video conference environment or maydiffer from a virtual 3D video conference environment.

Step 72 may include obtaining information regarding avatars related toparticipants—an avatar of a participant includes at least a face of aparticipant in a conference call. An avatar of the participant may bereceived once, once or more per period, once or more per conferencecall.

Step 73 may include virtually positioning the avatars related to theparticipants in the virtual 3D environment. This can be done in anymanner, based on previous sessions of the participants, based onmetadata such as job title and/or priority, based on the roles in theconference call—for example initiator of the call, based on preferencesof the participants, and the like. Step 73 may include generating avirtual representation of the virtual 3D environment populated by theavatars of the participants.

Step 74 may include receiving information regarding spatialrelationships between the locations of the avatars of the participantsand the directions of gaze of the participants and updating at least theorientation of the avatars related to the participants within thevirtual 3D environment.

FIG. 18 illustrates method 1600.

Method 1600 may be for updating a current avatar of a person, and mayinclude steps 1601, 1602, 1603, 1604 and 1605.

Step 1601 may include calculating current locations, within a twodimensional (2D) space, of current face landmark points of a face of aperson. The calculating may be based on the current avatar, and one ormore current acquisition parameters of a 2D camera; wherein the currentavatar of the person may be located within a 3D space.

Step 1602 may include calculating target locations, within the 2D space,of face landmark points of the face of the person; the calculating ofthe target locations may be based on one or more images acquired by the2D camera.

Step 1603 may include calculating correspondences between the currentlocations and the target locations.

Step 1604 may include calculating, based on the correspondences,locations of the face landmark points within the 3D space.

Step 1605 may include modifying the current avatar based on thelocations of the face landmark points within the 3D space.

The current face landmark points may be only edge points of the currentface landmarks.

The current face landmark points may include edge points of the currentface landmarks and non-edge points of the current face landmarks.

The calculating of the correspondences may include applying an iterativeclosest point (ICP) process, wherein the current locations may beregarded as source locations.

The locations of the target face landmark points within the 3D space maybe represented by barycentric coordinates.

The current avatar may include a reference avatar and a current 3Ddeformation model, wherein the modifying of the current avatar mayinclude modifying the current 3D deformation model without substantiallymodifying the reference avatar.

The current 3D deformation model may be a 3D morphable model (3DMM).

The method may include repeating, for a current image and untilconverging, steps 1601-1605.

Step 1602 may include segmentation.

FIG. 18 also illustrates an example of method 1650 for conducting a 3Dvideo conference between multiple participants.

Method 1650 may include steps 1652, 1654 and 1656.

Step 1652 may include receiving initial 3D participant representationinformation for generating the 3D representation of the participantunder different circumstances. This receiving may be based on videos orimages of the participant acquired specifically for video conferencingor for other purposes. The received information may also be retrievedfrom additional sources such as social networks and the like. Theparticipant information may be related to the participants of aconference call—for example a first participant and a secondparticipant.

Step 1654 may include receiving, by a user device of a first participantand during the 3D video conference call, second participantcircumstances metadata indicative of one or more current circumstancesregarding a second participant.

Step 1656 may include updating, by the user device of the firstparticipant, a 3D participant representation of the second participant,within a first representation of virtual 3D video conferenceenvironment.

The different circumstances may include at least one out of differentimage acquisition conditions, different directions of gaze, differentviewpoints of a viewer, different expressions, and the like.

The initial 3D participant representation information may include aninitial 3D model and one or more initial texture maps.

FIG. 18 also illustrates an example of method 1900 for conducting a 3Dvideo conference between multiple participants.

Method 1900 may include steps 1910 and 1920.

Step 1910 may include determining, for each participant and multipletimes during the 3D video conference, updated 3D participantrepresentation information within the virtual 3D video conferenceenvironment.

Step 1920 may include generating, for at least one participant andmultiple times during the 3D video conference, an updated representationof a virtual 3D video conference environment, the updated representationof virtual 3D video conference environment represents the updated 3Dparticipant representation information for at least some of the multipleparticipants.

The 3D participant representation information may include a 3D model andone or more texture maps.

The 3D model may have separate parameters for shape, pose andexpression.

Each texture map may be selected and/or augmented based on at least oneout of shape, pose and expression. The augmentation may include,modifying values due to lighting, facial make-up effects (lipstick,blush and the like . . . ), adding or removing facial hair features(such as beard, moustache), accessories (such as eyeglasses, ear buds)and the like.

Each texture map may be selected and/or augmented based on at least oneout of shape, pose, expression and angular relationship between a faceof the participant and an optical axis of a camera that captures animage of face of the participant.

The method may include repetitively selecting for each participant, aselected 3D model out of multiple 3D models of the participant; andsmoothing a transition from one selected 3D model of the participant toanother 3D model of the participant.

Step 1910 may include at least one out of:

-   -   a. Using one or more neural network for determining the updated        3D participant representation information.    -   b. Using multiple neural networks for determining the updated 3D        participant representation information, wherein different neural        networks of the multiple neural networks may be associated with        different circumstances.    -   c. Using multiple neural networks for determining the updated 3D        participant representation information, wherein different neural        networks of the multiple neural networks may be associated with        different resolutions.

The method may include selecting an output of at least one neuralnetwork of the multiple neural networks based on a required resolutionwherein the multiple neural networks operate on different outputresolutions and the one with the resolution that is closest to therequired resolution is selected.

FIG. 18 further illustrates an example of method 2000 for conducting a3D video conference between multiple participants.

Method 20 may include steps 2010 and 2020.

Step 2010 may include determining, for each participant, updated 3Dparticipant representation information within the virtual 3D videoconference environment, that represents participant. The determining mayinclude estimating 3D participant representation information of one ormore hidden areas of a face of a participant that may be hidden from thecamera that captures at least one visible area of the face of theparticipant.

Step 2020 may include generating, for at least one participant, anupdated representation of virtual 3D video conference environment, theupdated representation of virtual 3D video conference environmentrepresents the updated 3D participant representation information for atleast some of the multiple participants.

The method may include estimating 3D model hidden areas and one orhidden parts texture maps.

The estimating 3D participant representation information of one or morehidden areas may be executed by using one or more generative adversarialnetworks.

The method may include determining a size of the avatar.

Multi-Resolution Neural Networks for Rendering 3D Models of People.

In a 3D virtual meeting application there may be a need to presentparticipants of the 3D virtual video conference with very high qualityin the virtual 3D video conference environment. To achieve a highrealism level, neural networks may be used to create a 3D model of thehead and body of each participant. A neural network may be also used tocreate a texture map of the participants and the 3D model and texturemaps can then be rendered to create an image of the participants thatcan be viewed from different angles.

If there are more than two participants in the meeting, then eachparticipant may wish to zoom-in and out in order to see otherparticipants from close-up or rather zoom-put to see many or all of theparticipants in the meeting.

Using a neural network to create the 3D model and texture maps of theparticipants may be typically a computationally intensive operation.Running the neural network many times for rendering the images of manyparticipants may not be scalable and may not be possible using astandard computer as the number of needed computations may be high andthe computer's resources may be exhausted without achieving real-timerendering. Alternatively, it may be very costly using a network ofcomputers on the cloud.

According to this embodiment, a set of networks may be trained toproduce 3D models and texture maps at different levels of detail (numberof polygons in the 3D model and number of pixels in the texture map).

For example, very high-resolution networks may create a 3D model with10,000 polygons and a 2D texture map with 2000×2000 pixels. Ahigh-resolution network may create a 3D model with 2500 polygons and a2D texture map with 1000×1000 pixels.

A medium-resolution networks may create a 3D model with 1500 polygonsand a 2D texture map with 500×500 pixels. A low-resolution network maycreate a 3D model with 625 polygons and a 2D texture map with 250×250pixels.

In an embodiment, all these networks can be one network with severaloutputs after a varying number of layers. For example, the output of thefinal network would be a texture map with 2000×2000 pixels and theoutput of the previous layer would be a texture map with 1000×1000pixels.

During run-time, the software determines what would be the size of theimage of each participant in the meeting according to the zoom levelthat the user may be using.

According to the required size following the zoom level, the methoddetermines which networks should be used to create the 3D model and the2D texture map with the relevant level of details. In this way, smallerfigures require a lower resolution network that results in a lowernumber of calculations per network. Accordingly, the total number ofcalculations required to render the images of many people would bereduced compared to the running of many full resolution networks.

According to an embodiment a texture map of a face of the person can begenerated based on texture maps of different areas of the face.

One of the texture maps of an area of the face (for example of a facelandmark, of an eye, mouth, and the like) may be of a higher resolution(more detailed) than from a texture map of another area of the face (forexample the area between the eye and nose may have a higher resolutionthan the cheeks or forehead). See, for example FIG. 20 in which a higherresolution texture map of the eyes may be added to lower resolutiontexture maps of other areas of the face to provide a hybrid texture map2222.

The texture maps of the different areas may be of two or more differentresolution levels. The selection of the resolution per texture map maybe fixed or may change over time. The selection may be based onpriorities of the different areas. The priority may change over time.

According to another embodiment, texture maps of different areas of theface may be updated and/or transmitted at different frequenciesaccording to the frequency of change of those areas. For example eyesand lips may change more frequently than nostrils or eyebrows.Accordingly, the texture maps of the nostrils and eyebrows may beupdated less often that those for eyes and lips. This way the number ofcalculations is further reduced—in comparison to a situation in whichthe texture maps of the nostrils and eyebrows are updated at the higherfrequency of update of the texture maps of the eyes and lips.

The resolutions of the different face area texture maps may be based onan additional parameter such as available computational resources,memory resource status, and the like.

The generating of the texture map of the face from texture maps ofdifferent areas of the face may be executed in any manner and mayinclude, for example, smoothing the borders between the differenttexture maps of the different areas, and the like. Any reference made tothe face may be applied mutatis mutandis to the entire person or to anyother body organ of the person.

FIG. 18 also illustrates an example of method 2100 for generating atexture map used during a video conference such as a virtual 3Dconference.

Method 21 may include steps 2110, 2120 and 2130.

Step 2110 may include obtaining (for example generating or receiving inany manner) multiple texture maps of multiple areas of at least aportion of a 3D object; wherein the multiple texture maps may include afirst texture map of a first area and of a first resolution, and asecond texture map of a second area and of a second resolution, whereinthe first area differs from the first area and the first resolutiondiffers from the second resolution.

Step 2120 may include generating a texture map of the at least portionof the 3D object, the generating may be based on the multiple texturemaps.

Step 2130 may include utilizing the visual representation of the atleast portion of the 3D object based on the texture map of the at leastportion of the 3D object during the video conference.

Multi-View Texture Maps

There may be provided generating highly realistic faces—it may beapplicable to other objects.

Generating high-quality and very realistic images and videos or facesand bodies may be a general problem in computer graphics.

This can be applied to the creation of movies or to computer games amongother uses.

It can also be applied for creating a 3D video conferencing applicationin which users may be seated in a common space and 3D avatars representthe participants and move and talk according to the actual movements ofthe users as captured by a standard webcam.

To create a realistically looking 3D representation of a face, head orbody, 3D models and 2D texture maps may be created offline, and thenrigged. Rigging means creating handles in the 3D model that enablemoving different parts of the model, much like muscles do in a realbody.

The 3D model and texture maps should include views of the external partsof the body and face but also internal parts such as the mouth, teethand tongue. They should enable to move body parts such as the eyelids topresent open and closed eyes.

To create highly realistic looking images or videos, very high-level 3Dmodels may be used—typically with up to 100,000 polygons in a model of ahead.

In addition, the texture maps should include descriptions of all theinternal and external body/head parts in high resolution.

In addition to the texture maps, material maps or reflectivity maps maybe needed in order to enable the rendering engine to simulate nonuniform (non-Lambertian) reflections of light from the body and face,for example reflections from a moist or oily skin or from the glossyeyes.

Creating such 3D models and 2D texture and material maps typicallyrequires a well-equipped studio with many cameras and controlledlighting. This limits the use of these models to offline andpost-production use cases.

Due to all this, rendering a highly realistic body and head may be acomplex process that requires many calculations. Such an amount ofcalculations may not be able to be processed on any standard computer atreal time and at a high frame rate (at least 30 frames per second).

This problem becomes even more serious if many bodies and heads need tobe rendered in each image, for example, if there may be manyparticipants in a 3D meeting.

Instead of using a 3D model with a very high number of polygons, texturemaps with many options for internal and external parts andmaterial/reflection maps, there is provided an alternative solution thatwould require much fewer calculations and also enable the real-timerendering of many bodies and faces.

The solution may be based on capturing images or videos of a person fromvarious points of view, e.g., from the front, sides, back, top andbottom.

This can be done by scanning the head with a handheld mobile phonecamera or by turning the head in front of a fixed camera such as awebcam or a mobile phone camera fixed on a tripod or any other device.Images of the person may also be acquired by other methods and othersources, including extracting from social networks or other Internetresources, using scanned photographs of the person and the like,

During the scanning process, the person may be asked to performdifferent facial expressions and talk. To scan a whole body, the usermay be asked to pose in different body poses or to move and change posescontinuously.

The images that are collected in this process may be used to train aneural network or several neural networks that produce a 3D model of thehead and/or body as a function of the required pose and expression andas a function of the viewpoint.

In addition, a viewpoint dependent texture map may be produced as afunction of the required pose and expression and as a function of theviewpoint.

The 3D model and texture map may be used to render an image of the headand/or body or the person.

Since the 2D texture map that is outputted by the neural network may bedependent on at least one of viewpoint, pose and expression, it shouldonly include the information that may be relevant to rendering the imagefrom that at least one of viewpoint, pose and expression. This enablesthe 3D model of the head or body to be less accurate as missing 3Ddetails such as skin wrinkles may be compensated by the fact that thosedetails appear in the 2D texture image. Similarly, there may be no needto create a rigged model of open or closed eyelids as the texture of anopen or closed eyelid may be found in the 2D image and projected on the3D model.

In fact, the 3D model can be highly inaccurate as it omits many facialdetails and does not consider small muscles and their movements. It alsodoes not include internals not the moving facial parts as mentionedabove, while the 2D image presents the appearance from a certainviewpoint and not from multiple viewpoints. This means that inaccuraciesin the 3D model will not reflect in the rendering of the 3D model andthe texture map from a certain viewpoint.

As a result, the 3D model used for rendering the images, does not needto be very detailed and does not include many polygons. Typically, itcan have several thousand or several hundreds of polygons, compared totens of thousands or hundreds of thousands of polygons in conventionalsolutions.

This allows the fast, real-time rendering of a head and/or body in realtime on a computational device with an inexpensive processing unit.

Furthermore, the 3D model and 2D texture maps may be outputted bydifferent networks as a function of the resolution of the desired outputimage. Low resolution images would be rendered based on low resolutionpolygon 3D models and low-resolution texture maps that may be output byneural networks with fewer coefficients requiring fewer computations.

This further allows the rendering of several heads and/or bodies at oncein one image using a low cost and low power computational device such asa laptop without a GPU, a mobile phone or a tablet.

Also note that the solution does not require a studio and may be basedon a single camera. It does not require a complex system with manycameras and illumination sources and does not require controlledlighting.

FIG. 19 illustrates an example of method 2200 for 3D video conference.

Method 2200 may include steps 2210 and 2220.

Step 2210 may include determining, for each participant, updated 3Dparticipant representation information within the virtual 3D videoconference environment, that represents participant. The determining mayinclude compensating for difference between an actual optical axis of acamera that acquires images of the participant and a desired opticalaxis of a virtual camera.

Step 2220 may include generating, for at least one participant, anupdated representation of virtual 3D video conference environment, theupdated representation of virtual 3D video conference environmentrepresents the updated 3D participant representation information for atleast some of the multiple participants.

The updated representation of virtual 3D video conference environmentmay include an avatar per participant of the at least some of themultiple participants.

A direction of gaze of a first avatar within the virtual 3D videoconference environment may represent a spatial relationship between a(a) direction of gaze of a first participant that may be represented bythe first avatar and (b) a representation of the virtual 3D videoconference environment displayed to the first participant.

A direction of gaze of a first avatar within the virtual 3D videoconference environment may be agnostic to the actual optical axis of thecamera.

A first avatar of a first participant within the updated representationof the virtual 3D video conference environment appears in the updatedrepresentation of the virtual 3D video conference environment as beingcaptured by the virtual camera.

The virtual camera may be located at a virtual plane that virtuallycrosses the eyes of the first participant of the first participant.

The method may include receiving or generating participants appearanceinformation about head poses and expressions of the participants, anddetermining the updated 3D participant representation information toreflect the participant appearance information.

The method may include determining a shape of each of the avatars.

FIG. 19 also illustrates an example of method 2300 for generating animage from a certain viewpoint of an object that may be threedimensional.

Method 2300 may include step 2310 of rendering an image of the object,based on a compact 3D model of the object and at least onetwo-dimensional (2D) texture map associated with the certain viewpoint.

The rendering may include virtually placing texture generated from theat least one 2D texture map on the compact 3D model.

The method may include selecting the at least one 2D texture mapsassociated with the certain viewpoint out of multiple 2D texture mapthat may be associated with different texture map viewpoints.

The rendering may be also responsive to a requested appearance of theobject.

The object may be a representation of an acquired object that may beacquired by a sensor.

The rendering may be also responsive to an appearance parameter of theacquired object.

The acquired object may be a participant of a three-dimensional (3D)video conference.

The method may include receiving the at least one 2D texture map fromone or more neural networks.

FIG. 19 further illustrates an example of method 2400 for conducting a3D video conference between multiple participants.

Method 2400 may include steps 2410, 2420 and 2430.

Step 2410 may include receiving second participant metadata and firstviewpoint metadata by a first unit that may be associated with a firstparticipant, wherein the second participant metadata may be indicativeof a pose of a second participant and an expression of the secondparticipant, wherein the first viewpoint metadata may be indicative of avirtual position from which the first participant requests to view anavatar of the second participant.

Step 2420 may include generating, by the first unit, and based on thesecond participant metadata and the first viewpoint metadata, a secondparticipant representation information; wherein the second participantrepresentation information may include a compact 3D model of the secondparticipant and a second participant texture map.

Step 2430 may include determining, for the first participant and duringthe 3D video conference, a representation of virtual 3D video conferenceenvironment, wherein the determining may be based on the secondparticipant representation information.

The method may include generating each one of the compact 3D and thesecond participant texture map in response to the second participantmetadata and first viewpoint metadata.

The generating of at least one of the compact 3D model and the secondparticipant texture map may include feeding the second participantmetadata and first viewpoint metadata to one or more neural networkstrained to output the at least one of the compact 3D model and thesecond participant texture map based on the second participant metadataand first viewpoint metadata.

The compact 3D model may include less than ten thousand points.

The compact 3D model may consist essentially of five thousand pointssuch as for the FLAME model (https://flame.is.tue.mpg.de/home).

The determining of the representation of the virtual 3D video conferenceenvironment may include determining an estimate of an appearance of thesecond participant in the virtual 3D video conference environment basedon the second participant texture map; and amending the estimate basedon a compact 3D model of at least the second participant.

The amending may include amending the estimate based on concealment andillumination effects related to compact 3D models of one or moreparticipants of the 3D conference video.

Attentiveness and Mood Estimation from Video

Due to Covid19 many in person meetings have been replaced by videoconferencing calls.

Such calls may be lengthy, and participants may lose their attentivenessor focus and may also be tempted to do other things in parallel to themeeting such as browse the internet, read emails or play with theirphones.

In many cases, it may be important for some of the meeting participantsto know if the other participants may be attentive, (i.e. payingattention to the meeting) and how the other participants feel—they maybe, for example, content, sad, angry, stressed, agree or disagree withwhat is said, etc.

Example cases for such video conferencing call may be associated, forexample with school lectures, university lectures, sales meetings, andteam meetings managed by a team manager.

There may be provided a solution for analyzing videos and estimating theattentiveness of participants and especially those who may be notactively participating and talking.

A database of videos from video conferencing meetings may be collected.

For every participant (or at least some of the participants) that appearin one or more of the videos, the video may be divided into parts inwhich the attentiveness and feelings of the user may be estimated to beconstant. In each part of each video, the attentiveness level andemotions may be estimated by using several possible means:

The participant may be asked how interested he/she was during that partof the meeting and what was their mood during that time.

-   -   a. An external annotator may be asked to estimate the        attentiveness and mood based on the appearance of the        participant, such as the head pose, eye movements and facial        expressions.    -   b. External devices may be used to measure the participants        heartbeat and other biological signals, as done by a polygraph        machine or other less sophisticated methods.    -   c. A computer software or an observer may verify whether the        participant was looking at another window on the computer screen        that may be unrelated to the meeting, i.e. not focusing        completely on the meeting.

For each part of each video a numerical score for the attentiveness maybe created or alternatively, the participant's attentiveness may beclassified into several classes such as “highly interested”,“interested”, “apathetic”, “bored”, “extremely bored” and“multi-tasking”.

In a similar manner, the user's mood may be estimated, e.g., “happy”,“content”, “sad”, “angry”, “stressed”.

Conversely, numerical values can be given to certain feelings such ashappiness, relaxation, interest, etc.

A neural network model may be trained to find the correlation betweenthe appearance of the participant in the video and the level ofattentiveness and mood.

In run time, a video may be supplied to the network and it outputs anestimate of the attentiveness level as function of time.

This output may be presented to some participants such as the host ormanager of the meeting (teacher, salesperson, manager) in order toimprove their performance or to aid certain other participants who mayhave lost attentiveness.

In an embodiment, the faces detected in the videos may be modelled by aneural network generating a parametric model that includes parametersregarding the head pose, eye gaze direction and facial expressions, asdescribed in previous patents.

Once a parametric model is found, only the parameters may be input tothe neural network that estimates the attentiveness level instead ofinputting the raw video.

The parameters may be inputted as a temporal series of parameters sothat the temporal change in expressions, head and eye movements may betaken into consideration. For example, if there is no change in theparameters coding the facial expression or head and eyes direction for aprolonged period of time, the network may learn that this may be a signof inattentiveness.

Such a method may be beneficial as it reduces the amount of data thatmay be input into the network that estimates the level of attentiveness.

In another embodiment, the output of the video analysis network may becombined with data collected by a computer software.

Such additional data can be:

-   -   a. Are other windows being viewed on the screen?    -   b. Is the user typing or may be the mouse clicked during a        video-conferencing meeting?    -   c. Using eye gaze tracking, the direction in which a person may        be looking can be estimated.

The method may estimate whether the user may be looking at the personwho may be talking in a video conferencing app or at other people orjust gazing around.

Using eye gaze detection, the method can also estimate whether the useris looking at areas of the screen that is not occupied by the videoconferencing software, such as other open windows.

Using eye gaze detection, the method can estimate whether the user maybe reading text during the meeting.

The combination of all the data sources may be used to estimate whetherthe participant of the meeting may be multi-tasking during the meetingand paying attention to other tasks instead of the video meeting.

Note that the process mentioned above may be not limited to renderingimages of people and can be also used to render animals or any otherobjects.

FIG. 19 further illustrates an example of method 2500 for determining amental parameter of a participant in video conference video conference.

Method 2500 may include steps 2510 of applying a machine learningprocess on video of the participant acquired during the video conferenceto determine the mental state of the participant during the videoconference; wherein the mental state may be selected out of mood andattentiveness. The machine learning process was trained by a trainingprocess during which it was fed with training video segments of one ormore people and training mental state metadata indicative of the mentalstate of the one or more people participant during each of the trainingvideo segments.

The training mental state metadata may be generated in any manner—forexample by at least one out of:

-   -   a. Querying the one or more people.    -   b. Generated by an entity (medical staff, expert, and the like)        that differs from the one or more people.    -   c. Measuring one or more physiological parameters of the one or        more people during an acquisition of the training video        segments.    -   d. Generated based on interactions of the one or more people,        during the acquisition of the training video segments, with        components other than a display associated with the one or more        people.    -   e. Generated based on a direction of gaze of the one or more        people, during an acquisition of the training videos segments.

The one or more people may be the participant.

The video conference may be a three-dimensional (3D) video conference.

Method 2500 may include the training.

FIG. 18 further illustrates an example of method 2600 for determining amental state of a participant in video conference video conference.

Method 2600 may include steps 2610 and 2620.

Step 2610 may include obtaining participant appearance parameters duringthe 3D video conference. An example of such parameters is given in theFlame model (https://flame.is.tue.mpg.de/home).

Step 2620 may include determining the mental state of the participant,wherein the determining may include analyzing, by a machine learningprocess, the participant appearance parameters.

The machine learning process may be implemented by a thin neuralnetwork.

The analyzing occurs repetitively during the 3D video conference.

The analyzing may include tracking after one or more patterns of valuesof the appearance parameters.

The method may include determining, by the machine learning process, andbased on the one or more patterns, the mental state of the participant.

The method may include determining a lack of attentiveness whereinduring at least a predetermined period the one or more appearanceparameters may be substantially unchanged.

The mental state may be a mood of the participant.

The mental state may be an attentiveness of the participant.

The determining may be further responsive to one or more interactionparameter regarding an interaction of the participant within a deviceother than a display.

The participant appearance parameters may include a direction of gaze ofthe participant.

FIG. 19 illustrates an example of method 2700 for determining a mentalparameter of a participant in video conference video conference.

Method 2700 may include steps 2710 and 2720.

Step 2710 may include obtaining participant interaction parametersduring the 3D video conference.

Step 2720 may include analyzing, by a machine learning process, theparticipant interaction parameters to determine the mental parameter ofthe participant.

FIG. 19 also illustrates an example of method 2800 for determining amental state of a participant in video conference video conference.

Method 2800 may include steps 2810, 2820 and 2830.

Step 2810 may include obtaining participant appearance parameters duringthe 3D video conference.

Step 2820 may include obtaining participant computer traffic parametersindicative of computer traffic exchanged with a computer of theparticipant, the computer of the participant being utilized forparticipating in the 3D video conference.

Step 2830 may include determining the mental state of the participant,wherein the determining may include analyzing, by a machine learningprocess, the participant appearance parameters, and the participantcomputer traffic parameters.

FIG. 19 also illustrates an example of method 2900 for determining amental state of a participant in video conference video conference.

Method 2900 may include steps 2910, 2920 and 2930.

Step 2910 may include obtaining participant appearance parameters duringthe 3D video conference.

Step 2920 may include obtaining participant computer traffic parametersindicative of computer traffic exchanged with a computer of theparticipant, the computer of the participant being utilized forparticipating in the 3D video conference.

Steps 2910 and 2920 may be followed by step 2930 of determining themental state of the participant, wherein the determining may includeanalyzing, by a machine learning process, the participant appearanceparameters, and the participant computer traffic parameters.

It should be noted that the total number of calculations that may needto be performed may be bounded not by the number of people that appearin the Field Of View (FOV) but rather by the resolution of the view. Ifthe screen resolution remains constant, then, for example, widening theFOV may result in more participants shown but with smaller sizes thatneed to be captured and rendered.

Multiple Participants in One Visual Sensing Unit

Existing conference call systems assume one participant per camera.Accordingly, one tagged name appears per camera even if more than oneperson uses it. This can lead to misunderstandings as to who theparticipants are, especially if other participants can't recognize them.

It may be beneficial to provide accurate representations of eachparticipant that is captured by a camera—even when multiple participantsare captured by a single camera or by a visual sensing unit that mayinclude more than a single camera.

Participants may be appear in one or more representations of a virtual3D video conference environment and each participant may be representedby an avatar.

It should be noted that non-participants may also appear in the one ormore representations of a virtual 3D video conference environment.Accordingly—a person that should appear in at least one representationof a virtual 3D video conference environment may be regarded as arelevant person. The relevant person may be a participant or anon-participant.

The method may start by visual information analysis—such as detectingthe number of persons that are captured by the visual sensing unit, andattempting to identify the persons. Any identification process may beused. For example, face detection and recognition.

Once a person is detected—the method may determine whether the person isrelevant or non-relevant and may be ignored of.

Assuming that a person is relevant—then his/her image (part of the imageacquired by the visual sensing unit) may be segmented. The segmentationmay include associating different segments with each participant'sclothes or other possible accessories (watches, eyeglasses, jewelry,etc.). Optionally the relevant person may be allowed (for example byreceiving inputs from the user) to identify the different segments.

In a virtual 3D video conference environment where each participant isrepresented by an avatar, each one of the relevant persons captured by athe visual sensing unit can be represented by a different avatar.Without identifying that there are multiple relevant persons, such asystem would malfunction.

Within this framework, it may occur that one of the relevant personsgestures or possibly looks at another of the relevant persons of thesame camera. This could then be reflected by the behavior of theavatars. As an example, if one of the relevant persons hands an objectto another relevant person, this action can then be reflected in thevirtual 3D video conference environment and the avatar correspondingwith the first relevant person could be shown handing a similar objectto the avatar corresponding to the second relevant person.

Optionally, the system would also have a temporal tracking mechanismwith some temporal memory. This would allow participants to move in andout of the view of the camera while still being identified separately.This tracking may be based on face-recognition, tracking of clothes'colors or similar methods.

Another option is that when more than one person appears in the cameraview, the system may be directed to show only a subset of those personsin the video conference. For example, it is quite customary, when videoconferences are taken from home, that other household persons andanimals—children, pets, spouses—(deemed to be irrelevant) appearoccasionally within the view of the camera. In this case, the systemwould be directed not to show the non-relevant persons or animals withinthe video conference.

FIG. 21 illustrates examples of multiple methods—method 3000, method3001, method 3003 and method 3200.

Method 3000 is for conducting a virtual 3D video conference betweenmultiple participants.

The execution of the virtual 3D video conference may include displayingmultiple representations of a virtual 3D video conference environment tomultiple participants devices. The calculations required for theprovision of the virtual 3D video conference may be executed by one ormore computational systems other than any of the multiple participantsdevices, may be executed solely (or almost solely) by the multipleparticipants devices, may be executed by a combination of one or moreparticipants' devices and one or more other systems.

Information related to the presence of relevant persons within a fieldof view of a visual sensing unit related to any of the participants maybe sent to one or more other participant devices, may be sent to one ormore other systems, may be subjected to filtering rules, transmissionblocking rules, or any other rules related to the processing and/ortransmission and/or display of any indication related to the multiplepersons.

The participant devices may display a plurality of representations ofvirtual 3D video conference environments—usually the representation ofvirtual 3D video conference environment differs from one participantdevice to another. The presence of relevant one or more persons may bereflected in at least some of the plurality of representations ofvirtual 3D video conference environments.

Method 3000 may start by step 3010 of acquiring visual information, by avisual sensing unit related to a certain participant.

Step 3010 may be followed by step 3020 of identifying one or morepersons that appear in the visual information. In some cases multiplepersons may appear in the visual information. In some other cases onlyone person appears in the visual information. In some further cases noperson appears in the visual information.

If a single person appears or no person appears in the visualinformation then step 3020 may be followed by step 3029 of responding tothe detection or one or no persons.

If multiple persons appear in the visual information, then step 3020 maybe followed by step 3030 of finding, out of the multiple persons, atleast one relevant person.

A relevant person is a person whose presence may be indicated to atleast one participant (or participant device) of the virtual 3D videoconference. At least an indication about a presence of a relevant personmay be sent outside a participant device of the certain participant.

The presence of a relevant person may be represented (or at least is acandidate for being represented) in a virtual 3D video conferenceenvironment displayed to one or more participant of the virtual 3D videoconference. A participant may determine not to receive an indication ofthat person, and/or the display of said presence may be subjected tofiltering and/or displaying rules. The relevant person may be aparticipant or may not be a participant.

Step 3030 may include at least one of the following:

-   -   a. Determining which of the multiple persons are participants of        the virtual 3D video conference.    -   b. Determining whether a participant is a relevant person.    -   c. Determining whether a non-participant of the 3D video        conference is a relevant person.    -   d. Applying a face recognition process. Any known face        recognition process can be applied. This may require an        initialization process of acquiring an image of a face of a        participant.    -   e. Applying any biometric identification process—even other than        the face recognition process. Any known biometric recognition        process can be applied. This may require an initialization        process of acquiring biometric information of a participant.    -   f. Storing identification information about the at least one        relevant person for at least a certain period of time following        an appearance of the certain participant and the person. This        may reduce computational resources usage—as there is no need to        initiate another relevancy determination process.    -   g. Identifying any of the at least one relevant persons after        the at least one relevant person exited the field of view of the        visual sensing unit and then re-entered the field of view of the        visual sensing unit, wherein the identifying is based on the        identification information. This may provide a certain “memory”        as a person identified as relevant may leave the field of view        for up to a predefined time and still be regarded as relevant.    -   h. Continuing to indicate that the relevant person is within the        field of view of the visual sensing unit—even during predefined        periods in which the relevant person exits the field of view—in        order to reduce computational resources and required to        re-generate and/or update a virtual 3D video conference        environment—and also may reduce communication resources usage        (no need to send information regarding the virtual 3D video        conference environment updates). This may also provide a        smoother virtual 3D video conference environment. The method may        use a hysteresis or any other smoothing mechanism when deciding        whether to update information related to a presence or absence        of a relevant person within the virtual 3D video conference        environment. The predefined periods may be of any length—but        usually them may be relatively short—for example up to a few        seconds, up to a predetermined fraction (for example up to 5,        10, 15, 20, 25, 30 percent of the scheduled duration of the        virtual 3D conference), may depend on an availability of        computational and/or memory and/or communication resources (for        example—may lengthen the predefined period of absence without        updating the virtual 3D video conference environment when there        are communication problems and/or reduction in communication        bandwidth and/or reduction or lack of computational resources        and/or of memory resources).

Step 3030 may be followed by step 3040 of responding to the finding, outof the multiple persons, at least one relevant person.

Step 3040 may include step 3041 of determining 3D entity representationinformation, for each of the at least one relevant person and step 3042of generating, for at least one participant, a representation of avirtual 3D video conference environment, based on the 3D entityrepresentation information for each of the at least one relevant person.

Steps 3010, 3020, 3030 and 3040 can be executed in relation to visualsensing unit or any of the participants.

Method 3001 is for conducting a virtual 3D video conference betweenmultiple participants.

Method 3001 may start by step 3010 of acquiring visual information, by avisual sensing unit related to a certain participant.

Step 3010 may be followed by step 3020 of identifying one or morepersons that appear in the visual information. In some cases multiplepersons may appear in the visual information. In some other cases onlyone person appears in the visual information. In some further cases noperson appears in the visual information.

If a single person appears or no person appears in the visualinformation then step 3020 may be followed by step 3029 of responding tothe detection or one or no persons.

If multiple persons appear in the visual information, then step 3020 maybe followed by step 3030 of finding, out of the multiple persons, atleast one relevant person.

Step 3030 may be followed by step 3040 of responding to the finding, outof the multiple persons, at least one relevant person.

Step 3040 may include step 3041 of determining 3D entity representationinformation, for each of the at least one relevant person and step 3042of generating, for at least one participant, a representation of avirtual 3D video conference environment, based on the 3D entityrepresentation information for each of the at least one relevant person.

Step 3040 may include step 3043 of searching for a physical interactionbetween the relevant persons. When finding the physical interaction—thenstep 3040 may also include generating of the representation of virtual3D video conference environment (for the at least one participant) maybe responsive to the physical interaction.

Method 3002 is for conducting a virtual 3D video conference betweenmultiple participants.

Method 3002 may start by step 3010 of acquiring visual information, by avisual sensing unit related to a certain participant.

Step 3010 may be followed by step 3020 of identifying one or morepersons that appear in the visual information. In some cases multiplepersons may appear in the visual information. In some other cases onlyone person appears in the visual information. In some further cases noperson appears in the visual information.

If a single person appears or no person appears in the visualinformation—then step 3020 may be followed by step 3029 of responding tothe detection or one or no persons.

If multiple persons appear in the visual information—then step 3020 maybe followed by step 3030 of finding, out of the multiple persons, atleast one relevant person.

Step 3030 may be followed by step 3040 of responding to the finding, outof the multiple persons, at least one relevant person.

Step 3040 may include step 3041 of determining 3D entity representationinformation, for each of the at least one relevant person and step 3042of generating, for at least one participant, a representation of avirtual 3D video conference environment, based on the 3D entityrepresentation information for each of the at least one relevant person.

Step 3040 may include step 3045 of generating a same-visual-sensing-unitindication that is indicative that the relevant persons are captured bya single visual sensing unit. See, for example, same-visual-sensing-unitindication 3099 of FIG. 23 .

The same-visual-sensing-unit indication may be included in therepresentation of virtual 3D video conference environment (for the atleast one participant). The visual sensing unit may include a firstcamera and a second camera. The same-visual-sensing-unit indication mayor may not be generated wherein one of the relevant persons is within afield of view of the first camera, and one other of the relevant personsis within a field of view of the second camera.

Method 3003 is for conducting a virtual 3D video conference betweenmultiple participants.

Method 3003 may start by step 3010 of acquiring visual information, by avisual sensing unit related to a certain participant.

Step 3010 may be followed by step 3020 of identifying one or morepersons that appear in the visual information. In some cases multiplepersons may appear in the visual information. In some other cases onlyone person appears in the visual information. In some further cases noperson appears in the visual information.

If a single person appears or no person appears in the visualinformation then step 3020 may be followed by step 3029 of responding tothe detection or one or no persons.

If multiple persons appear in the visual information, then step 3020 maybe followed by step 3030 of finding, out of the multiple persons, atleast one relevant person.

Step 3030 may be followed by step 3040 of responding to the finding, outof the multiple persons, at least one relevant person.

Step 3040 may include step 3041 of determining 3D entity representationinformation, for each of the at least one relevant person and step 3042of generating, for at least one participant, a representation of avirtual 3D video conference environment, based on the 3D entityrepresentation information for each of the at least one relevant person.

Step 3040 may include step 3047 of determining for each relevant personof relevant persons captured by a same visual sensing unit, whether therelevant person speaks or not.

Step 3047 may be followed by responding to the determination of whethera relevant person talks or not in the representation of virtual 3D videoconference environment displayed to one or more participant.

The responding may include allowing only a single speaking person to bedisplayed in a virtual 3D environment.

Method 3200 is for conducting a 3D video conference between multipleparticipants.

Method 3200 may include an initialization step 3202. The initializationstep 3202 may include receiving initial 3D participant representationinformation for generating the 3D representation of the participantunder different circumstances. The 3D participant representationinformation may include a 3D model and one or more texture maps.

Method 3200 may include step 3210 of receiving direction of gazeinformation regarding a direction of gaze of a participant. Thedirection of gaze information may represent a detected or estimateddirection of gaze of the participant.

Step 3210 may be followed by step 3220 of estimating whether (a) a gazeof a certain participant is aimed towards a person located within afield of view of a visual sensing unit that also captures at least ahead of the participant, or whether (b) the gaze of the person isdirected towards a representation of a person within a virtual 3D videoconference environment.

Step 3220 may be followed by step 3230 of determining whether (i) a 3Drepresentation of the person should appear within the virtual 3D videoconference environment, and/or (ii) determining whether to update thedirection of gaze of a representation of the participant—to show that heis looking at the person.

The determining may be responsive to different parameters—forexample—whether the gaze of the certain participant was directed to theperson, whether the gaze of the person is directed towards arepresentation of a person within a virtual 3D video conferenceenvironment, whether the person is a participant of the current virtual3D conference, whether he/she participated in any previous virtual 3Dconference, and the like.

Step 3230 may include at least one of the following:

-   -   a. Deciding that the 3D representation of the person should not        appear within the virtual 3D video conference environment when        the person is not a participant.    -   b. Allowing a non-participant to appear in the virtual 3D video        conference environment.    -   c. Performing the determining based on a rule or definition        provided by the certain participant. It may also be based on        rules provided by other participants—the rules may define which        persons should appear in their representation of the virtual 3D        video conference environment.    -   d. Performing the determining based on at least a size or an        estimated age of the person. For example—children may be        excluded from being represented.    -   e. Performing the determining based on bandwidth of        communication and/or computational resource status. For        example—when the available bandwidth of a communication link or        channel from a certain participant device to another device or        system is below a certain threshold—the decision may tend to        ignore the person—for example especially if the person is not a        participant—yet for another example—when the person is not        associated with an existing avatar.    -   f. Identifying the person using face recognition.    -   g. Identifying the certain participant and the person using an        identification process.    -   h. Performing the determining based on stored identification        information about the person and the certain participant that is        stored for at least a certain period of time following an        appearance of the certain participant and the person.    -   i. Identifying the person after the person exited the field of        view of the visual sensing unit and then re-entered the field of        view of the visual sensing unit. The identifying is based on the        identification information.

Step 3230 may be followed by step 3240 of responding to thedetermination of step 3230.

Step 3240 may include at least one out of steps 3240(a)-3240(n):

-   -   a. Generating person information regarding an appearance of the        person—when it is determined that a 3D representation of the        person should appear within the virtual 3D video conference        environment. The person information may include the 3D        representation of the person, or information that may be        processed by a rendering engine or other image processor to        provide an avatar or any other 3D representation of the person        within one or more representations of the virtual 3D video        conference environment. The person may or may not be associated        with an avatar. When associated with an existing avatar—then the        person information may include instructions of how to update the        avatar (for example provide circumstance information). When not        associated with an existing avatar there may be a need to        generate a new avatar or use an existing avatar—even if not        initially associated with the person.    -   b. Updating the direction of gaze of a representation of the        participant—to show that he/she is looking at the person—when        determining to update the direction of gaze. This may include        updating a circumstance regarding the participant and the like.    -   c. Generating a same visual sensing unit indication that is        indicative that the person and the certain participant are        captured by the same visual sensing unit. The visual sensing        unit may include a first camera and a second camera, wherein the        certain participant is within a field of view of the first        camera, and the person is within a field of view of the second        camera.    -   d. Searching (when determining that the person should appear)        for physical interaction between the person and certain        participant.    -   e. Determining, when a physical interaction is found, whether it        should be represented in one or more representations of the        virtual 3D video conference environment—and if so—determining        how it should appear—and generating information that will cause        the physical interaction to be represented in the one or more        representations.    -   f. Generating a 3D person representation information that        indicates that the person is not a participant.    -   g. Maintaining unchanged a direction of gaze of the certain        participant within the virtual 3D video conference environment        during a change in a direction of gaze of the certain        participant from the person to a visual representation of the        person within the virtual 3D video conference environment.    -   h. Generating an updated representation of virtual 3D video        conference environment that includes an avatar per participant        of the at least some of the multiple participants.    -   i. Determining relevancy of segments of updated 3D participant        representation information, and selecting which segments to        transmit, based on the relevancy and available resources.    -   j. Determining relevancy of segments of updated representation        of virtual 3D video conference environment information, and        selecting which segments to transmit, based on the relevancy and        available resources.    -   k. Generating a 3D model and one or more texture maps of 3D        participant representation information of a participant.    -   l. Estimating 3D participant representation information of one        or more hidden areas of a face of a participant that are located        outside a field of view of a camera that captures at least one        visible area of the face of the participant.    -   m. Determining, for each participant, of the updated 3D        participant representation information by changing an        illumination condition.    -   n. Determining, for each participant, of the updated 3D        participant representation information by adding or changing        wearable item information.

All steps 3240(a)-3240(n) may be executed by the same device or system,but one or more steps of steps 3240(a)-3240(n) may be executed bydifferent devices and/or systems. For example—step (h) may be generatedby a rendering engine located at a computerized system or participantdevice that differs from the participant device that executes step3240(a).

There are multiple representations of the virtual 3D video conferenceenvironment (for example one per participant)—and steps 3230 and/or 3240may be done per each one of the representations. The update itself (theinclusion of the visual information—for example, the appearance of theperson) may differ from one representation to the other.

Multiple participants of the virtual 3D conference are associated withmultiple participant devices. There may also be a computerized systemthat differs from any of the multiple participant devices.

Various steps of method 3200 may be executed by at least one of thecomputerized systems, and one or more of the multiple participantsdevices.

FIG. 22 illustrates an image 3009 which is a part of a video acquired bya visual sensing unit. Image 3009 captures first person 3004 and secondperson 3005. There is a physical interaction between the persons as theyhug each other. The physical interaction may be represented in thevirtual 3D video conference environment.

In one example both persons are regarded as relevant persons and theiravatars 3004′ and 3005′ appears in a representation 3009′ of a virtual3D video conference environment (only part of the environment is shown).

In another example only the first person is regarded as a relevantperson and its avatar 3004′ (and not the avatar of the second person)appears in a representation 3009″ of a virtual 3D video conferenceenvironment (only part of the environment is shown).

FIG. 22 also illustrates an image 3008 which is a part of a videoacquired by a visual sensing unit. Image 3008 captures a third person3007 looking at a fourth person 3008.

In one example both persons are regarded as relevant persons and theiravatars 3006′ and 3007′ appear in a representation 3008″ of a virtual 3Dvideo conference environment (only part of the environment is shown).Additional avatars of other relevant persons 51-53 are also shown.

FIG. 23 illustrates examples of directions of gaze of a participant. Theupper part of the figure illustrates the fifth participant 85 as lookingat the 3D visual representation (51) of the first participant 81 withinthe virtual 3D video conference environment (in panoramic view 41).

A second example illustrates the fifth participant 85 as looking at thefirst participant 81—as in this example both participants may use thesame device and are captured by the same visual capture unit.

In both cases the virtual 3D video conference environment may be updatedto indicate that the fifth participant looks at the first participant(actual or 3D participant representation). There may be provided anindication about whether the fifth participant is looking at the actualfirst participant or at his representation.

Sharing Content

It is important that video conferences be as efficient as possible asthey are susceptible to communications issues and lack the benefits offace-to-face meetings. One issue which may limit the efficiency of videoconferences has to do with sharing of information usually achieved bysharing files and screens.

Existing solutions such as Zoom, Webex and Microsoft Teams allow usersto share an application or their whole screen during a conference. Someof these applications even allow multiple users to share content at thesame time. If participants want to share content prior to the meeting inorder to help other participants prepare or come informed to theconference, they need to do so over some additional application. Forexample, they would send out materials over mail to the otherparticipants. If other participants are interested in the material afterthe meeting, it needs to be sent out to them.

The suggested method, while directed at 3D video conferencing, can alsobe beneficial to other systems—specifically also to 2D videoconferencing environments.

According to the suggested method, it is possible for each participantto share more than one piece of data during a conference call. Moreover,information can be shared easily with other participants prior to theirmeeting and can be viewed following its end.

According to the suggested method, when a meeting is planned andinvitations are sent out, a shared folder is created in the cloud—muchlike a folder within Google Drive or Microsoft Teams. A link to thedrive is sent to the future participant and can be the same link usedlater for the meeting itself.

The host of the meeting is allowed to set permissions (access controlrules) for access to the shared folder. These permissions may includeallowing to upload documents, edit them, create subfolders and the like.The following paragraphs detail some possible options assuming they areallowed to the participants.

Participants can upload word processed documents, presentations,spreadsheets and the like (collectively called “documents”) to thefolder. They can also create sub-folders within the folder based ondifferent criteria. Participants may be able to set specific settings tothe documents they uploaded to the same folder.

One possible option is to send notifications to participants whendocuments are uploaded or when they are modified.

Participants may upload documents to the shared folder during themeeting itself.

An additional option is to create one or more documents collaborativelyby one or more of the participants during the meeting (as, for example,Google Drive allows).

During the meeting, participants may decide they want to share one ormore of the documents in the shared folder at a specific time.

Having a shared folder allows the following novel benefits: If aparticipant can't join the meeting or has communication issues, theirdocuments may still be viewed by other participants. It is simple for asingle participant to share more than one piece of material at a time.As mentioned above, existing solutions only allow sharing one app, onewindow or one screen at a time. Sharing information prior to meetingsdoes not require multiple applications as the video conferencingapplication takes care to update participants when documents areavailable.

Following the end of the meeting, it is possible not to remove or deletethe shared folder for any defined period of time. One additionalpossibility is to add a recording of the meeting to the same sharedfolder. This, then, allows participants that may have missed all or partof the meeting to find all the relevant information in one place. Italso allows participants that took part in the meeting to go over theinformation at their own pace after the meeting is over.

The suggested method also enables immediate sharing of the material withother participants without the need to send out the material after themeeting. If a summary and/or action items are captured for the meeting,they can also be placed in the shared folder.

FIG. 24 illustrates method 3400 for sharing content during a virtual 3Dvideo conference.

Method 3400 may start by at least one of steps 3410, 3420 and 3430.

Step 3410 may include inviting multiple participants to join a virtual3D video conference.

Step 3420 may include creating a shared folder dedicated for storingshared content items, wherein the shared content is accessible during atleast during the virtual 3D video conference. The shared content itemscomprise at least one of text, document, video unit, and audio unit.

Step 3430 may include enabling access, to the multiple participants, tothe shared folder; wherein the access is governed by one or more accesscontrol rule. This may include adding a link to the invitations of step3410, or performing any enabling step with, following or regardless ofstep 3410.

The access control rule may determine retrieval of shared content,uploading of content to the shared folder, and the like.

One or more access control rule may be responsive to the availability ofstorage resources in the shared folder—for example preventing uploadwhen a size of to content to be uploaded exceeds a first size threshold(the threshold may be determined per participant, per type ofparticipant—organizer, participant, and the like), when the participantreaches a second aggregate size of uploaded content from theparticipant.

One or more access control rule may be responsive to the bandwidthavailability of a communication link to the shared folder and/or fromthe shared folder.

The access may be enabled—starting before the beginning of theconference call, starting at the conference call, and the like.

The access may be terminated at the end of the conference call, or afterthe end of the conference call.

Steps 3410, 3420, and 3430 may be followed by step 3440 of conductingthe virtual 3D video conference, wherein the conducting includes sharingat least one of the content items.

Step 3440 may include recording the virtual 3D video reference.

The sharing may be executed based, at least in part, on one or moresharing rules. For example, all participants may share any contentwithin the shared folder. Yet for another example—the sharing rules mayimpose limitations on the manner of sharing by one or more participant.

The one or more sharing rules may be included in the one or more accesscontrol rules.

The one or more sharing rules may not be included in the one or moreaccess control rules.

Step 3440 may be followed by an additional step 3450 executed at the endor following the end of the virtual 3D conference.

Step 3450 may include at least one of:

-   -   a. Deleting the shared folder dedicated after the completion of        the virtual 3D video conference.    -   b. Maintaining the shared folder dedicated after a completion of        the virtual 3D video conference and enabling access to the        shared folder after the completion of the virtual 3D video        conference.    -   c. Maintaining the shared folder dedicated until a predefined        time period after a completion of the virtual 3D video        conference and enabling access to the shared folder until a        predefined time period after the completion of the virtual 3D        video conference.    -   d. Maintaining the shared folder dedicated after a completion of        the virtual 3D video conference and applying after completion        access control rules for accessing the shared folder.    -   e. Maintaining the shared folder dedicated after a completion of        the virtual 3D video conference and adding a recording of the        virtual 3D video conference to the shared folder.

One, some or all of steps 3410, 3420, 3430, 3430 and 3450 may be managedby a virtual 3D video conference application.

FIG. 25 illustrates users' devices 4000(1)-4000(R) (and 4000(r), rranges between 1 and R), network 4050, remote computerized system 4100(that may include a virtual 3D video conference router 4111), and sharedfolder 4105 that includes multiple M shared content items4105(1)-4105(M) (and 4105(m), m ranges between 1 and M). FIG. 25 alsoillustrates invitations 4106(1)-4106(R) sent by user device 4000(r) thatinvites other participants to access shared folder and participate inthe virtual 3D video conference. During the virtual 3D video conferencevarious signals (VC related signals) 4108 are exchanged with the userdevices.

The shared folder may be implemented in any manner—for example by theremote computerized system 4100 or any other unit of system. A recording4109 of the virtual 3D video conference is illustrated as being storedin the virtual folder.

FIG. 25 also illustrates various rules 4104(1)-4104(N) (collectivelydenoted 4104) that may include sharing rules, access control rules, andthe like.

A rule may be applied on all participants, on some of the participantsor only one participant.

FIG. 26 illustrates two examples of a first timing diagram 3480 and asecond timing diagram 3480′.

First timing diagram 3480 illustrates the following sequence of events:opening shared folder and/or informing participants about the sharedfolder 3482, starting access to the shared folder 3483, start of theconference call 3485, end of the conference call 3486, and terminationof the shared folder 3487.

There may be multiple other timing relationships between these events.

The virtual 3D conference occurs between the start of the conferencecall 3485 and the end of the conference call 3486.

In first timing diagram, the conference call is recorded and may beavailable to participants till, for example, the termination of theshared folder 3487. The recording may be available in the sharedfolder—or may be provided in any other manner.

Second timing diagram 3480 illustrates the following sequence of events:(a) opening shared folder and/or informing participants about the sharedfolder 3482 that occurs concurrently to the starting access to theshared folder 3483, (a) start of the conference call 3485, and (b) endof the conference call 3486 that occurs concurrently with thetermination of the shared folder 3487.

Foreground and Background

It is often important in VC systems to differentiate between theforeground and background. In this context, the background is the partof the scene captured by the participant's camera which has lessimportance than other parts of the scene. A part with less importancemay be modified or removed altogether as its appearance does not have arole in the conference or meeting taking place. In fact, existingsolutions often allow the modification of the background.

This is often done in order to replace the apparent background of aparticipant with a more appeasing background or one that is chosen for amultitude of reasons such as commercial reasons, in order to create aspecific ambience or other reasons.

With the increase of importance of video conferencing systems, it isimportant that this differentiation between foreground and background beas accurate as possible. This task is particularly important in upcoming3D VC environments where only an avatar of participants and possiblysome accessories that they may be using are presented to the otherparticipants.

Some solutions may differentiate between foreground background on aframe-to-frame basis. This method works well when a method known as“green screen” is used. When using the method, the background has aknown color (usually green) and it is achieved by placing the screenbehind the participant. Each pixel captured by the camera, is inspected.If its color matches that of the known screen color, the pixel isassumed to be a part of the background. This method may be augmented inseveral ways. Regardless, most environments which host the participantdo not have such a screen handy and other methods are used.

Existing methods typically differentiate between foreground andbackground by first assuming that all humans are part of the foreground.In order to identify humans, they typically look for skin colors first.Then they attempt to find some reasonable surrounding shape or coloraround the skin color before they determine that they identify people inthe captured picture. This often leads to body parts appearing anddisappearing in a haphazard way from the presented picture as sometimesthey are conceived as being part of the background and are replacedwhile at other times, they are considered part of the foreground andtherefore are not replaced.

Another drawback of this system is that if a participant wants to addsome accessories such as an easel or a white board, these would appearto be a part of the background and when it is replaced they would not beshown.

The current method, while directed at 3D video conferencing, can also bebeneficial to other systems.

According to the current method, the background and foreground aredifferentiated based on temporal tracking and are not performed on aframe-by-frame basis.

According to this method, the captured picture is segmented first toidentify so called blobs. In addition to identifying if these blobs arepart of the foreground or background based on their staticcharacteristics (such as color or surrounding colors) as in today'smethods, blobs are also classified based on their temporal or dynamiccharacteristics. Blobs that move, change their appearance, color orother characteristic may be classified as belonging to the foreground orat least be classified as having a high probability as belonging to theforeground. In some cases, blobs with periodical movements (such asfans, flipping pieces of paper, etc.) can be categorized as belongingthe background or as having a high probability of belonging to thebackground.

An option is to let the user decide at some time—preferably as the userjoins the conference but this could be ongoing—to choose whether a blobbelongs to the foreground or background. An alternative is to have amachine learning system in place to learn the temporal and spatialbehavior of blobs that belong to the foreground and background. Thissystem would learn from user choices as to whether include a blob in theforeground or background. One way of implementing this would be througha Neural Network.

Once the background is known, the participant can add accessories andthey would appear to the other viewers in the conference. Additionally,if a whiteboard or similar device is used, the writing on it—and theboard itself—would not be classified as part of the background andtherefore the system would continuously show it to other participants.

FIG. 27 illustrates method 3500 for foreground and backgroundsegmentation related to a virtual three-dimensional (3D) videoconference.

Method 3500 may start by step 3510 of segmenting each image of multipleimages of a video stream, to segments. Each segment may have one or moreproperties that are substantially constant.

The segmenting may include applying a blob analysis, wherein thesegments are blobs. The segmenting may apply segmenting methods thatdiffer from blob analysis.

Step 3510 may be followed by step 3520 of determining temporalproperties of the segments.

Step 3520 may be followed by step 3530 of classifying each segment as abackground segment or a foreground segment, based at least in part, onthe temporal properties of the segments.

Step 3530 may include at least one out of:

-   -   a. Classifying a static segment as a background segment.    -   b. Classifying a segment that exhibits a periodical change as a        background segment.    -   c. Searching for one or more face segments.    -   d. Classifying each face segment as a foreground segment.    -   e. Classifying a segment that is not a face segment and exhibits        a periodical change as a background segment.    -   f. Using a machine learning process to classify each segment as        a background segment or a foreground segment; wherein the        machine learning process was trained to perform the classifying        based on classification inputs received from users.    -   g. Classifying based, at least in part, on feedback from a user.    -   h. Displaying to a user segments of at least one of the images;        receiving from the user classification inputs relating to at        least some of the segments, wherein the classifying is also        based on the classification inputs.    -   i. Classifying, as foreground segments, one or more items added        to a virtual 3D video conference environment displayed to at        least one participant of the virtual 3D conference.

FIG. 27 also illustrates method 3501 for foreground and backgroundsegmentation related to a virtual three-dimensional (3D) videoconference.

Method 3501 may start by step 3510 of segmenting each image of multipleimages of a video stream, to segments. Each segment may have one or moreproperties that are substantially constant.

The segmenting may include applying a blob analysis, wherein thesegments are blobs. The segmenting may apply segmenting methods thatdiffer from blob analysis.

Step 3510 may be followed by step 3520 of determining temporalproperties of the segments.

Method 3520 may be followed by step 3525 of providing to a userinformation, and receiving feedback from the user.

Step 3525 may include at least one out of:

-   -   a. Providing to a user temporal information about temporal        properties of the segments.    -   b. Receiving feedback from the user such as classification        inputs relating to at least some of the segments.    -   c. Displaying to a user the segments and providing to the user        temporal information about temporal properties of the segments.    -   d. Receiving from the user feedback such as classification        inputs relating to at least some of the segment.

Step 3525 may be followed by step 3535 of classifying each segment as abackground segment or a foreground segment, based at least in part, onthe feedback. The feedback may include for example, the classificationinputs.

Step 3535 may be responsive to the feedback and to the temporalproperties of the segments. Step 3535 may include any sub-steps of step3530—and each sub-step may be modified based on the feedback—or havingits output and the feedback from the user taken into account.

FIG. 28 illustrates an example of an image segmented to foreground andbackground.

Image 3490 captures a person 3493, a ventilator 3494, and a grey wall.When operated the ventilator may perform a periodically changingmovement and can be regarded as belonging to the background 3492. Theperson itself forms the foreground 3491.

Touch-Ups—Denoising Makeup

Existing video conference systems, such as Zoom and Microsoft Teamsallow participants to add “filters” that improve or otherwise modifytheir appearance. For example, it is possible to add makeup such aslipstick or blush. It is also possible to add gadgets such aseyeglasses, or appear to add moustaches and beards, modify the haircolor and style and so on.

Such filters can be used not only to add makeup or gadgets. They canalso be utilized to touch up (such functions known as photoshopping) anddenoise the appearance of the participants (so as to reduce noise addedby the camera, lighting conditions, etc.).

There is a need to provide an accurate, and efficient (in terms ofmemory resource usage and/or computational resource usage) method fordetermining an appearance of participants within a virtual 3Denvironment.

Performing segmentation on a frame-to-frame basis to identify facialparts in order to enhance them is highly ineffective and suffers fromnoises introduced to the images. For example, in each frame, the lipsare identified and then the relevant color of lipstick is applied.Similarly, the chin is detected and possibly also the inclination of theface and a beard is placed on top of it in the correct angle. This is acostly operation. Specifically, if a person chooses to add lipstick,blush, eyeglasses, a beard and also modify the hair color, this requiresthat detecting all the relevant facial parts needs to occur tens oftimes each second (depending on the frame rate which would typically benot less than 30 per second). Once the parts are detected, the touch upsand make up are then added for each frame.

This costly action also limits the possibility of denoising theappearance of the participant. The main reason for this to be performedthis way is that the systems do not maintain a model of the specificparticipant's face.

There is provided a method in which the participant appears in themeeting environment through avatars. Any of the mentioned above methodsfor generating such representations may be used.

A 3D model of the participant or at least of the participant's head andface and/or torso may be obtained. This model (and one or more texturemaps) can be manipulated or used as a basis to create the avatar of theparticipant.

The different facial parts of the participant are an integral part ofthe 3D model.

In order to add touch ups and makeup, the 3D model may be updated once.For example, a chosen color is added to the lips as lipstick. Like otherparts of the 3D model, the voxels corresponding to the lips then have areflectance associated with it and as an avatar is rendered, thereflectance allows a realistic appearance of the lips. Similarly, anychosen color is applied to the cheeks to appear as rouge. To make thisappear more realistic, the chosen color can be combined with theoriginal skin color in a linear or other way, in intensity or spatially,so that it appears as if the model actually has rouge on its cheeks.Then once the models are manipulated to create the avatar, all theadditions are already in place. FIG. 34 illustrates an example of aparticipant 4301 having lipstick on its lips. FIGS. 35, 36 and 37illustrate an avatar 4301′ of the participant of without lipstick, thelips 4304 of the avatar without lipstick and the avatar 4301″ withlipstick, respectively.

Moreover, this method allows easy denoising and “photoshopping”.Denoising is possible since the model should not be susceptible to noiseintroduced by the camera, lighting or other source. Since the model'sexistence is ongoing, noise introduced during the capture of a singleimage by the camera, can easily by cleaned by averaging the reflectancevalue of each point in the model over time.

“Photoshopping” such modifying facial parts (modifying noses, liftingcheekbones, removing “double chins”, etc.) is performed once on the 3Dmodel instead of performing these actions again and again for eachframe. So once the 3D model is created, all the effects are performed onthe model. In other words, the model's cheekbones are lifted or itsdouble chin is removed. These adjustments are then noted and whenever anew image is captured by the camera, all that is needed to create a newavatar is to understand the new position, orientation and gaze of theperson. These are then applied to the adjusted 3D model.

FIG. 29 illustrates method 3600.

Method 3600 refers to a first participant and to a second participant.This is for simplicity of explanation. The first and second participantsmentioned above may be any pair of participants. Any step of method 3600may be applied on any combination of participants.

Method 3600 may include an initialization step 3602.

The initialization step 3602 may include receiving, by a user device ofa first participant of the virtual 3D video conference, reference secondparticipant 3D representation information for generating a secondparticipant 3D representation under different constraints. wherein thedifferent constraints may include at least one out of (a) a touch upconstraint, (b) a makeup constraint, and (c) one or more circumstancesconstraint.

The constraints—for example makeup and/or touch up may be provided by aparticipant even when the actual participant does not actually wear themakeup specified in the makeup constraint.

At least one other constraint may be determining by other means—forexample image analysis, and the like.

Examples of circumstances constraints are illustrated in method 3200.

For example—the different constraints may include different directionsof gaze of the second participant, different expressions of the secondparticipant, different lighting conditions, different fields of view ofthe camera, and the like.

The initial 3D participant representation information may include aninitial 3D model and one or more initial texture maps.

The 3D participant representation information may include a 3D model andone or more texture maps.

The initial second participant 3D representation information mayrepresent a modified representation of the second participant. It is“modified” in the sense that the modified representation differs from anactual appearance of the second participant. The modified representationdiffers from the actual appearance of the second participant by at leastone out of size, shape and location of a face element.

Method 3600 may include step 3610 of receiving, by the user device ofthe first participant and during the 3D video conference call, secondparticipant constraints metadata indicative of one or more currentconstraints regarding a second participant. The second constraintmetadata may refer to any aspect of the appearance of the avatar and itssurroundings—for example makeup, hair appearance (facial hair, headhair, hair on any body part) and/or, inclusion or removal of accessories(for example glasses, sunglasses, earing, neckless, bracelets, piercing)and/or clothes (for example—the user may request that his avatar willinclude clothes that he does not currently wear, that his avatar will bewithout clothes that he actually wears, may introduce any otherdifference between the actual appearance of the user and his avatar'sappearance) the shape and/or size and/or colors of the accessories,inclusion or removal of a virtual or actual tattoo and/or a scar, theshape and/or size and/or color of the virtual or actual tattoo, and thelike. Any of the above may be implemented by defining the 3D model ofthe user to include any of the requested constrains metadata—andallowing to render any change with the rest of the 3D model of the userwhen rendering the avatar of the user. For example—the user may appearin front of a camera, without a shirt and have the system dress thatuser with a virtual shirt. This virtual shirt may be a part of the 3Dmodel and then would require only rendering with the rest of the modelwhen rendering an avatar of the user.

Step 3610 may be followed by step 3620 of updating, based on the secondparticipant constraints metadata, and by the user device of the firstparticipant, a 3D participant representation of the second participant,within a first representation of virtual 3D video conferenceenvironment.

Step 3620 may be followed by step 3630 of generating an avatar of thesecond participate based on 3D participant representation information ofthe second participant.

Step 3630 may include step 3632 of generating a makeup version of a faceelement based on a makeup free appearance of the face element and aselected makeup. Thus—the selected makeup can be virtually added to orplaced over or otherwise merged with the makeup free face appearance ofthe face element. The makeup version of the face element may maintainthe same during one or more 3D conference calls, from its definition bythe participant until the participant decides to change the makeupversion. According to one example the makeup does not change as otherparameters such as the direction of gaze change.

Step 3632 may include generating a makeup version of a face element byapplying a linear function on voxels of a makeup free appearance of theface element and a selected makeup.

The makeup free version may be replaced by any reference representationof the second participant—which can be modified according to one or moremakeup constraints.

Method 3600 may include step 3670 of obtaining an updated referencesecond participant 3D representation information for generating anupdated second participant 3D representation under differentconstraints. The updated reference second participant 3D representationinformation may replace the initial reference second participant 3Drepresentation under different constraints.

The updated reference second participant representation information maybe generated by performing denoising.

There are multiple representations of the virtual 3D video conferenceenvironment (for example one per participant)—and steps 3630 and/or 3670may be done per each one of the representations. The update itself (theinclusion of the visual information—for example, the appearance of theperson) may differ from one representation to the other.

Multiple participants of the virtual 3D conference are associated withmultiple participant devices. There may also be a computerized systemthat differs from any of the multiple participant devices.

Various steps of method 3600 may be executed by at least one of thecomputerized systems, and one or more of the multiple participants'devices.

FIG. 30 illustrates a women 4301 that is a participant of a virtual 3Dconference that views a representation of the virtual 3D conferenceenvironment.

Audio Quality Improvement in Video Conferencing

It is important that participants hear each other well and clear withinvideo conferences as these settings are not natural and typicallyrequire more extensive attention on the part of participants than inface-to-face meetings. Nevertheless, background noises are often heardduring online meetings. In other cases, problems with microphones orother system components reduce the quality and clarity of what isspoken, reducing the effectiveness of such meetings.

Methods of noise cleaning exist today. Some solutions, such as Krisp,clear voices which are not human. This specific application is installedin the client side of the video conference. In other words, participantsthat do not have it installed do not gain from its benefits. Meanwhile,the noisy or unclear soundtrack is transmitted to all the participants.

The suggested method utilizes image and video processing to enhance theaudio in video conferences. This is generally possible because withinVideo Conferencing environments, participants typically have camerasviewing and capturing them.

In a nutshell, the enhancement is performed by visually analyzing themouth, lips and tongue movements of the participants—or a subset ofthose that may appear to a camera viewing a speaker.

Using machine learning techniques, a system is trained to learn howthese movements correspond to different sounds. This training can beperformed with Neural Networks or other methods.

The training can be performed on whole words and sentences.Additionally, or alternatively, it can be performed only on a subset of“sounds”. For example, in the English language, it is generally agreedthat there are forty four phonemes or distinct sounds, with somevariation based on accent and articulation.

Such a system, when viewing a video conferencing participant speaking,may make educated assumptions regarding the sounds that the speaker ismaking. These assumptions may then be used in two ways:

-   -   a. Clean background noises by removing sounds that do not appear        to have come from the speaker.    -   b. Improve the quality of the audio transmitted from the system,        for example, when the participant's microphone is malfunctioning        or even if it is muted by mistake. (“Unmuting by force” may be        an optional setting of the video conference, set separately by        each participant and/or by the meeting's host).

These audio corrections may be performed at the speaker's system or at acentral location, depending on available resources or based on otherconsiderations.

It is also possible to have participants say some words or some soundsin order for the system to calibrate itself to the specific participant.This may be performed only one, at the beginning of meetings, whenparticipants join them or once every number of meetings.

FIG. 31 illustrates method 3700 for audio quality improvement related toa participant of a virtual three dimensional (3D) video conference.

Method 3700 may start by step 3710 of determining participant generatedaudio, by a machine learning process and based on image analysis of avideo of the participant obtained during the virtual 3D videoconference.

The machine learning process may be trained to convert image analysisoutputs to participant generated audio. The machine learning process maybe trained to convert video to participant generated audio.

The method may include training the machine learning process orreceiving a trained machine learning process.

Step 3710 may be followed by step 3720 of generating participant relatedaudio information based at least on the participant generated audio. Theparticipant related audio information, once provided to a computerizedsystem of another participant, causes the computerized system of theother participant to generate participant related audio of higherquality (or at least not lower) than participant audio when theparticipant audio is included in sensed audio that is sensed by an audiosensor that is associated with the participant.

Step 3720 may include at least one out of

-   -   a. Determining one or more audio processing features of an audio        processing algorithm; and applying the audio processing        algorithm on the sensed audio. The one or more audio processing        features may include any time domain and/or spectral domain        audio parameter such as a desired spectral range of the        participant related audio.    -   b. Applying an audio processing algorithm that may include        filtering process. The applying of the audio processing        algorithm may include filtering the sensed audio.    -   c. Applying a noise reduction algorithm on the sensed audio.    -   d. Applying a speech synthesis algorithm.

Step 3710 of determining may be applied even when an audio sensor (suchas a microphone) of the participant is mute.

Step 3710 may be preceded by or may include determining that the audiosensor is mute. The determination regarding the mute state of the audiosensor may be based on a comparison between the output of the audiosensor and the estimated audio that is outputted by the user—based onthe image analysis of the video of the participant.

When determining that the audio sensor is muted—step 3720 may includeapplying a speech synthesis algorithm.

Step 3720 may include step 3722 of determining, based on at least one ofa presence and a quality of the sensed audio, how to generate theparticipant related audio information.

Step 3722 may include selecting between (i) applying an audio processingalgorithm on the sensed audio, and (ii) applying a speech synthesisalgorithm.

Prediction

In a virtual 3D video conference participants may appear as avatars—orhave any other 3D representation.

This may involve creating 3D models of the participants. During themeeting, the participants sit in front of cameras. These capture theirmovement and some analysis is performed to find the participants' pose,orientation and expression. Then for each viewer of the meeting, anavatar of the participant is created so that the pose, orientation andexpression of the avatar appears in the viewer's field of view as itwould if the participant would physically be located in the meeting'senvironment.

This real-time process can be viewed as having two components: one doesthe analysis of the participant, and the other performs the rendering.

These two components may be co-located or not. For example, the analysisneeds to be performed only once for each participant but rendering mayneed to be performed multiple times—once for each viewer. Therefore, oneoption is to have the analysis performed at the participant's locationor at a central location while rendering, or parts of it, may beperformed at the location of each viewer. The analyzing component wouldneed to inform the rendering component of the changes in pose,orientation and expression so that the rendering component would renderthe avatar correctly.

In order to increase efficiency, reduce the possibility of errors andsave resources, it is important to reduce the amount of communicationsbetween these two components while maintaining a high degree ofreliability.

Some changes in movements or other characteristics may be predicted evenif for only short periods of time.

Consider the following over-simplified example. Suppose that aparticipant of a video conference nods and suppose also that images arecaptured every 33 milliseconds and that is also the interval betweenrenderings of the participant's avatar in the system of a viewer of themeeting. If the participant's head is moving upwards, it may be assumedthat this movement would continue for at least a few hundreds ofmilliseconds—say 200 milliseconds.

Under these assumptions, if the rendering component is able to predictthat this movement is occurring, it may be able to continuously renderthis movement without receiving any additional information from theanalyzing component, as long as the prediction is accurate—for exampleat least for a short period. If the actual movement is different thanthe predicted one, then the analyzing component may need to update therendering unit only with corrections to the predicted movement. Thesecorrections would include much less information than actual movementinformation. Therefore, this would allow much savings in communications.

For example—assuming that there is no prediction in the client. Theserver would need to send the full values. For example, every frame, theorientation should change upwards by 1 degree. If the client does haveprediction capabilities, then the server only needs to send corrections.For example, the client predicted upwards by 1 degree but in reality,the change was 1.0001 degrees, so the client only needs to send thevalue 0.0001.

If a prediction is good “in general” then if there is a correction to bemade, it would be of a lower order of magnitude than the fullprediction.

For example, if we predict a value of 100 but it turns out that the realvalue was 101, then the correction is only 1. Since the correctionstypically have much smaller values than the predictions, they can becoded with less bits. Using Huffman or Arithmetic coding would allow toallocate more communication bits if the correction is large, but thesewould then happen rarely.

If this is not the case, in other words, if the corrections are in thesame order of magnitude of the prediction, this practically means thatthere is no prediction.

A machine learning system may be trained to learn how to predict futurepose, orientation and expression based on their recent history.Predicting their near future may be performed for each one separately orbased on any combination of their history. A predictive model may belearned for each participant separately or for a “general” participant.

For example—an RNN may receive values of pose, orientation andexpression at any given time and learn to predict the next value.

This is much like NN are taught how to create texts by learning existingtexts or creating music by learning musical sequences.

Once a model is learned—it is shared with the analyzing and renderingcomponent.

A third component—a decider—may make a decision among three options:

-   -   a. Have the analyzing component transmit all the data to the        rendering component.    -   b. Have the rendering component render based only on the        predictive model.    -   c. Have the rendering component render based on the predictive        model with corrections sent by the analyzing model

It is assumed, for simplicity of explanation that the analyzingcomponent and the decision maker are within a first computerized unitand that the rendering component is within a second computerized unit.

The decision can be made by setting a threshold for the amount of datathat needs to be sent, or by setting a threshold on the consecutivenumber of times that corrections needed to be sent, or a combinationthereof.

The analyzing component aware of the predictive model used by therendering component. Therefore, it can evaluate what the renderingcomponent is doing if it is rendering based on the predictive model.

FIG. 32 illustrates method 3800 for predicting behavior changes of aparticipant of a virtual three dimensional (3D) video conference.

The prediction may reduce the volume of traffic between computerizedunit.

Method 3800 may be an iterative method. Each iteration may use a certainbehavioral predictor and once there is a need to use another behaviorpredictor—the next iteration begins. Each iteration is applied on a partof a virtual 3D video conference.

It is assumed that a first computerized unit performs various steps ofmethod 3800 and can be regarded as an analyzer and/or a transmitter.

A second computerized unit may receive information generated by a firstcomputerized unit and may display (or cause a display to show) arepresentation of the participant within a virtual 3D video conferenceenvironment.

The second computerized unit may be regarded as a receiver.

The first computerized entity may have access to a video of theparticipant, the video is acquired during the virtual 3D videoconference. The second computerized entity may not have no access to thevideo.

The first computerized entity may be an image analyzer. The secondcomputerized unit may be a rendering unit.

Each one of the first and second computerized units may be a participantdevice, a computerized system other that any participant device, and thelike.

Method 3800 may start performing, for each part of multiple parts of thevirtual 3D video conference the following steps:

-   -   a. Step 3810 of determining, by a first computerized unit, a        participant behavioral predictor to be applied by a second        computerized unit during the part of the virtual 3D video        conference. Any determination or selection method may be        applied—including any method for finding the best estimator, a        good enough estimator, and the like may be used.    -   b. Step 3820 of determining one or more prediction inaccuracies        related to the applying of the participant behavioral predictor        during the part of the virtual 3D video conference.    -   c. Step 3830 of determining whether to generate and transmit to        the second computerized unit prediction inaccuracy metadata that        is indicative of at least one prediction inaccuracy that affects        a representation of the participant within a virtual 3D video        conference environment presented to another participant of the        virtual 3D video conference during the part of the virtual 3D        video conference.

Step 3830 may be followed by step 3840 of generating and transmitting tothe second computerized unit the prediction inaccuracy metadata, whendetermining to generate and transmit to the second computerized unitprediction inaccuracy metadata.

The participant behavioral predictor may be determined and transmittedat the start of the part or before the part starts.

The one or more prediction inaccuracies may be generated and transmitted(if determined to do so) in real time to second computerized unit—toallow real time amendments to the representation of the participant.

Step 3840 may include transmitting an end of part indicator and/or anext behavioral predictor identifier, and the like.

Step 3480 may include sending to the second computerized entity,information about the participant behavioral predictor to be applied bythe second computerized unit.

Step 3810 may be based on a behavior of the participant during aprevious part of the virtual 3D video conference.

Step 3810 may include determining when the part ends and a new partstarts based on the one or more prediction inaccuracies related to theapplying of the participant behavioral predictor during the part.

Step 3810 may include determining when the part ends and a new partstarts based on the one or more prediction inaccuracies related to theapplying of the participant behavioral predictor during the part.

For example—the determination may be made when a size (Spi) oftransmitted information related to the prediction inaccuracies exceeds athreshold, when the Spi exceeds a size (Sdbi) of “direct” behavioralinformation that directly (without prediction) illustrates the behaviorof the participant, when the accuracy of the currently used participantbehavioral predictor is below a threshold, and the like.

Step 3830 may be based on the effect of the at least one predictioninaccuracy on the representation of the participant.

At least one of steps 3810, 3820, 3830 and 3840 may be executed by amachine learning process.

Steps 3810, 3820, 3830 and 3840 may be executed by the firstcomputerized unit.

Method 3800 may include step 3850 of determining, by the secondcomputerized unit, at each part, the participant behavioral predictor tobe applied by the second computerized unit.

Step 3850 may be followed by step 3860 of applying, by the secondcomputerized unit, at each part, the participant behavioral predictor,wherein the applying is affected by prediction inaccuracies informationreceived in real time from a first computerized unit.

FIG. 33 illustrates three periods of time within a virtual 3D videoconference 4201, 4202 and 4203. During the first period of time 4201,two participants 4211 and 4212 are at a certain position (as illustratedin image 4215)—both are looking at a display of a computer. Theparticipants move and change their direction of gaze (during a secondperiod of time 4202) so that they look at each other as illustrated byimage 4216—they may stay at the latter position during the third periodof time 4203.

A first behavioral predictor 4241 that was accurate during the firstperiod of time 4201 will not be accurate when the participants startmoving—and thus the first part 4231 of the virtual 3D video conferencemay end (and the second part 4232 may start) at the end of the firstperiod of time—or slightly afterwards (as shown in FIG. 33 )—and asecond behavioral predictor 4242 may be used.

The second behavioral predictor 4242 that was accurate during the secondperiod of time 4202 will not be accurate when the participants stopmoving—and thus the second part 4232 may end (and the third part 4233may start) at the end of the second period of time—or slightlyafterwards (as shown in FIG. 33 )—and a third behavioral predictor 4243may be used.

At least some of the mentioned above methods may be applicable mutatismutandis to 2D video conferences.

In the foregoing specification, the embodiments of the disclosure havebeen described with reference to specific examples of embodiments of thedisclosure. It will, however, be evident that various modifications andchanges may be made therein without departing from the broader spiritand scope of the embodiments of the disclosure as set forth in theappended claims.

Moreover, the terms “front,” “back,” “top,” “bottom,” “over,” “under”and the like in the description and in the claims, if any, are used fordescriptive purposes and not necessarily for describing permanentrelative positions. It is understood that the terms so used areinterchangeable under appropriate circumstances such that theembodiments of the disclosure described herein are, for example, capableof operation in other orientations than those illustrated or otherwisedescribed herein.

The connections as discussed herein may be any type of connectionsuitable to transfer signals from or to the respective nodes, units, ordevices, for example via intermediate devices. Accordingly, unlessimplied or stated otherwise, the connections may for example be directconnections or indirect connections. The connections may be illustratedor described in reference to be a single connection, a plurality ofconnections, unidirectional connections, or bidirectional connections.However, different embodiments may vary the implementation of theconnections. For example, separate unidirectional connections may beused rather than bidirectional connections and vice versa. Also,plurality of connections may be replaced with a single connection thattransfers multiple signals serially or in a time multiplexed manner.Likewise, single connections carrying multiple signals may be separatedout into various different connections carrying subsets of thesesignals. Therefore, many options exist for transferring signals.

Any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality may be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality.

Furthermore, those skilled in the art will recognize that boundariesbetween the above-described operations merely illustrative. The multipleoperations may be combined into a single operation, a single operationmay be distributed in additional operations and operations may beexecuted at least partially overlapping in time. Moreover, alternativeembodiments may include multiple instances of a particular operation,and the order of operations may be altered in various other embodiments.

Also, for example, in one embodiment, the illustrated examples may beimplemented as circuitry located on a single integrated circuit orwithin a same device. Alternatively, the examples may be implemented asany number of separate integrated circuits or separate devicesinterconnected with each other in a suitable manner.

However, other modifications, variations and alternatives are alsopossible. The specifications and drawings are, accordingly, to beregarded in an illustrative rather than in a restrictive sense.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word ‘comprising’ does notexclude the presence of other elements or steps then those listed in aclaim. Furthermore, the terms “a” or “an,” as used herein, are definedas one or more than one. Also, the use of introductory phrases such as“at least one” and “one or more” in the claims should not be construedto imply that the introduction of another claim element by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim element to embodiments of the disclosure scontaining only one such element, even when the same claim includes theintroductory phrases “one or more” or “at least one” and indefinitearticles such as “a” or “an.” The same holds true for the use ofdefinite articles. Unless stated otherwise, terms such as “first” and“second” are used to arbitrarily distinguish between the elements suchterms describe. Thus, these terms are not necessarily intended toindicate temporal or other prioritization of such elements. The merefact that certain measures are recited in mutually different claims doesnot indicate that a combination of these measures cannot be used toadvantage.

While certain features of the embodiments of the disclosure have beenillustrated and described herein, many modifications, substitutions,changes, and equivalents will now occur to those of ordinary skill inthe art. It is, therefore, to be understood that the appended claims areintended to cover all such modifications and changes as fall within thetrue spirit of the embodiments of the disclosure.

What is claimed is:
 1. A method for foreground and backgroundsegmentation related to a virtual three-dimensional (3D) videoconference, the method comprises: segmenting each image of multipleimages of a video stream, to segments, each segment has one or moreproperties that are constant, and comprises multiple pixels; determiningtemporal properties of the segments; searching for one or more facesegments; classifying each segment as a background segment or aforeground segment, based at least in part, on the temporal propertiesof the segments; wherein the classifying occurs after the segmenting andthe determining of the temporal properties of the segments; wherein theclassifying comprises classifying a segment that is not a face segmentand exhibits a periodical change as a background segment; detecting avideo conference communication object selected out of an earphone, acable connected to the earphone, a microphone, a three dimensionalglasses or a virtual reality headset; determining whether to display arepresentation of the video conference communication object during the3D conference; and preventing from displaying the representation of thevideo conference communication object during the 3D conference when itis determined, based on a selection made by another user, not to displaythe representation of the video conference communication object duringthe 3D conference.
 2. The method according to claim 1 further comprisinglearning objects typically chosen by users as a part of the foregroundand learning objects that are typically chosen by the users as a part ofthe foreground; and wherein the classifying is also responsive to thelearning.
 3. The method according to claim 1 comprising classifying eachface segment as a foreground segment.
 4. The method according to claim 1wherein the searching for the one or more face segments and theclassifying of the each segment are executed without using depthinformation.
 5. The method according to claim 1 further comprisingproviding to a user temporal information about temporal properties ofthe segments; receiving from the user classification inputs relating toat least some of the segments; and wherein the classifying is also basedon the classification inputs.
 6. The method according to claim 1 furthercomprising using a machine learning process to classify each segment asthe background segment or the foreground segment; wherein the machinelearning process was trained to perform the classifying based onclassification inputs received from users.
 7. The method according toclaim 1 wherein the segmenting comprises applying a blob analysis,wherein the segments are blobs.
 8. The method according to claim 1wherein the classifying is followed by classifying, as foregroundsegments, one or more items added to a virtual 3D video conferenceenvironment displayed to at least one participant of the virtual 3Dconference.
 9. A non-transitory computer readable medium for foregroundand background segmentation related to a virtual three-dimensional (3D)video conference, the non-transitory computer readable medium storesinstructions for: segmenting each image of multiple images of a videostream, to segments, each segment has one or more properties that areconstant, and comprises multiple pixels; determining temporal propertiesof the segments; searching for one or more face segments; classifyingeach segment as a background segment or a foreground segment, based atleast in part, on the temporal properties of the segments; wherein theclassifying occurs after the segmenting and the determining of thetemporal properties of the segments; wherein the classifying comprisesclassifying a segment that is not a face segment and exhibits aperiodical change as a background segment; detecting a video conferencecommunication object selected out of an earphone, a cable connected tothe earphone, a microphone, a three dimensional glasses or a virtualreality headset; determining whether to display a representation of thevideo conference communication object during the 3D conference; andpreventing from displaying the representation of the video conferencecommunication object during the 3D conference when it is determined,based on a selection made by another user, not to display therepresentation of the video conference communication object during the3D conference.
 10. The non-transitory computer readable medium accordingto claim 9 that stores instructions for classifying a static segment asa background segment.
 11. The non-transitory computer readable mediumaccording to claim 9 wherein the searching for the one or more facesegments and the classifying are executed without using depthinformation.
 12. The non-transitory computer readable medium accordingto claim 9 that stores instructions for learning preferences of a userand using feedback, from the user, regarding which textures are part ofthe foreground and which textures are part of the background, andwherein the classifying is also responsive to the learning.
 13. Thenon-transitory computer readable medium according to claim 9 furtherthat stores instructions for providing to a user temporal informationabout temporal properties of the segments; receiving from the userclassification inputs relating to at least some of the segments; andwherein the classifying is also based on the classification inputs. 14.The non-transitory computer readable medium according to claim 9 furtherthat stores instructions for using a machine learning process toclassify each segment as the background segment or the foregroundsegment; wherein the machine learning process was trained to perform theclassifying based on classification inputs received from users.
 15. Thenon-transitory computer readable medium according to claim 9 wherein thesegmenting comprises applying a blob analysis, wherein the segments areblobs.
 16. The non-transitory computer readable medium according toclaim 9 wherein the classifying is followed by classifying, asforeground segments, one or more items added to a virtual 3D videoconference environment displayed to at least one participant of thevirtual 3D conference.